Service Manual Logamax Plus GB142 (USA/CA) En 72149400 07 Instructions 12.2011 US

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Servicing instructions Condensing gas boiler
WARNING!
Improper installation, adjustment, alteration, service or maintenance can
cause injury, loss of life or property damage. Refer to this manual. For
assistance or additional information consult a qualified installer, service
agency or the gas supplier.
Notice:
This manual must be retained for future reference.
–Do not store or use gasoline or other flammable vapors and liquids in
the vicinity of this or any other boiler.
– What to do if you smell gas
•Do not try to light any boiler
•Do not touch any electrical switch; do not use any phone in your
building.
•Immediately call your gas supplier from a neighbor’s phone. Follow
the gas supplier’s instructions.
•If you cannot reach your gas supplier, call the fire department.
–Installation and service must be performed by a qualified
installer, service agency or the gas supplier.
Warning: If the information in these instructions is
not followed exactly, a fire or explosion may result
causing property damage, personal injury or death.
Logamax plus
GB142-24/30/45/60
7214 9400 (11/2011) US/CA
For installers
Please read thoroughly
before servicing
Preface
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!2
About these instructions
These Servicing Instructions contain important information to
diagnose and resolve issues concerning the GB142 boiler with
capacities 24, 30, 45 and 60 kW.
These Servicing Instructions are intended for specialist install-
ers, who have the necessary training and experience for working
on heating and gas systems.
Subject to technical changes!
Slight changes may be made to the illustrations, process steps
and technical data as a result of our policy of continuous
improvement.
Updating of documentation
Please contact us if you have any suggestions for improvements
or corrections.
Contents
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 3
1 Safety and general instructions 4
1.1 Designated use 4
1.2 Hazard definitions 4
1.3 The following instructions must be observed 4
1.4 Observe these instructions for heating
system water 5
1.5 Tools, materials and additional equipment 5
1.6 Inspection 5
1.7 Disposal 5
1.8 Abbreviations 6
2 Regulations and guidelines 7
3 Product description 8
4 Operation 9
4.1 Operating the BC10 basic controller 9
4.1.1 General 9
4.2 Menu structure of the BC10 basic controller 9
4.2.1 "Flue gas test" menu 10
4.2.2 "Service Mode" menu 11
4.2.3 "Manual Operation" menu 12
4.2.4 "Adjustments" menu 12
5Function 14
5.1 General 14
5.2 Structure diagram "Function" 15
6Symptoms 20
6.1.1 General 20
6.1.3 Display codes on the display of the BC10
basic controller 20
6.2 LED on the UBA 3 26
7 Diagnosis 27
7.1 Faults without a fault code 27
7.2 Faults with a fault code 46
8 Actions 84
8.1 Testing, measuring, adjusting and replacing
various components 84
8.1.1 Checking the UBA 3 fuse; replace if necessary 84
8.1.2 External connection board fuse 85
8.1.3 Checking the fan unit; 120 VAC control 86
8.1.4 Checking the fan unit; supply cord (120V AC) 87
8.1.5 Checking the fan unit; tacho cable 88
8.1.6 Replacing the fan unit 88
8.1.7 Checking the supply/return/safety/hot-water
temperature sensors 89
8.1.9 Checking the hot-water temperature sensor 91
8.1.10 Checking the supply/return/safety sensors cable 92
8.1.11 Checking the hot surface ignitor; control 92
8.1.12 Checking the hot surface ignitor; resistance 93
8.1.13 Checking the hot surface ignitor; supply cord 93
8.1.15 Testing the ionization current 95
8.1.16 Checking the ionization electrode; cable 95
8.1.17 Checking the ionization electrode;
replace if necessary 96
8.1.18 Checking the gas control valve;
cable connections 98
8.1.20 Checking the gas control valve;
cable connection between gas control valve
and UBA 3 installation base 99
8.1.21 Ohming out the gas control valve 100
8.1.22 Replacing the gas control valve 101
8.1.23 Checking the control unit; connections
to the boiler 104
8.1.24 Bleed the gas supply pipe 106
8.1.25 Measuring the inlet gas pressure
(flow pressure) 107
8.1.26 Measure and adjust the gas/air ratio 108
8.1.27 Measuring the carbon monoxide content (CO) 109
8.1.28 Transformer; replacing 109
8.1.29 Automatic air purging system; replacing 111
8.1.30 Burner; replacing 113
8.1.31 Sight glass; replacing 115
8.1.32 Condensate trap; replacing 116
8.1.33 Pressure sensor; replacing 116
8.1.34 Heat exchanger; replacing 117
8.1.35 UBA 3; replacing 125
9 Appendix 126
10 Spare parts 128
Safety and general instructions1
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!4
1 Safety and general instructions
Please observe these instructions in the interest of your own
safety.
1.1 Designated use
The boiler was designed for heating water for a space heating
system and generating hot water e.g. for domestic purposes.
The boiler is delivered with a BC10 basic controller and the
"Universal Automatic Burner Control Unit 3" (UBA 3) pre-
installed.
The boiler can be fitted with a modulating outdoor reset control
AM10 (scope of delivery) and an On/Off thermostat or relay
panel end switch (24 V) (accessories).
1.2 Hazard definitions
The following defined terms are used throughout the documen-
tation to bring attention to the presence of hazards of various risk
levels. Notices give important information concerning the life of
the product.
1.3 The following instructions must be
observed
– The boiler must only be used for its designated purpose,
observing the Installation Instructions.
– Only use the boiler in the combinations and with the accesso-
ries and spares listed.
– Other combinations, accessories and consumables must
only be used if they are specifically designed for the intended
application and do not affect the system performance and the
safety requirements.
– Maintenance and repairs must only be carried out by autho-
rized professionals.
– You must report the installation of a condensing gas boiler to
the relevant gas utility company and have it approved.
– You are only allowed to operate the condensing gas boiler
with the combustion air/flue gas system that has been specif-
ically designed and approved for this type of boiler.
– Please note that local permission for the flue system and the
condensate water connection to the public sewer system
may be required.
– You must also observe:
– the local building regulations stipulating the installation rules.
– the local building regulations concerning the air intake and
outlet systems and the chimney connection.
– the regulations for the power supply connection.
– the technical rules laid down by the gas utility company con-
cerning the connection of the gas burner fitting to the local
gas main.
– the instructions and standards concerning the safety equip-
ment for the water/space heating system.
– the Installation Instructions for building heating systems.
– The boiler must be located in an area where leakage of the
tank or connections will not result in damage to the area adja-
cent to the boiler or to lower floors of the structure. When
such locations cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed under the
boiler. The pan must not restrict combustion air flow.
– The boiler must be installed such that the gas ignition system
components are protected from water (dripping, spraying,
rain etc.) during boiler operation and service.
– The boiler must not be installed on carpeting.
– Do not restrict or seal any air intake or outlet openings.
– If you find any defects, you must inform the owner of the sys-
tem of the defect and the associated hazard in writing.
DANGER:
Indicates the presence of hazards that can
cause severe personal injury, death or substan-
tial property damage.
WARNING:
Indicates the presence of hazards that can
cause severe personal injury, death or substan-
tial property damage.
CAUTION:
Indicates presence of hazards that can cause
minor personal injury or property damage.
CAUTION:
Risk of electric shock.
Indicates presence of hazards due to electric
shock.
NOTICE:
Indicates special instructions on installation,
operation or maintenance that are important but
not related to personal injury or property
damage.
Safety and general instructions 1
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 5
1.4 Observe these instructions for heating
system water
– Thoroughly flush the system prior to filling.
Only use untreated main water to fill and top off the system.
– Do not use salt bedding exchangers to soften the water.
– Do not use inhibitors or other additives!
– No Toxic chemicals such as used for boiler treatment, shall
be introduced into the heating water used for space heating.
– The maximum permissible flow rate of the GB142-24/30 this
is 11 GPM (gal./min.), for the GB142-45 is 15 GPM and for
the GB142-60 is 20 GPM.
– When using oxygen-permeable pipes, e. g. for floor heating
systems, you must separate the system using heat exchang-
ers. Unsuitable heating system water promotes the formation
of sludge and corrosion.
This may damage the heat exchanger or affect its operation.
1.5 Tools, materials and additional equipment
For the installation and maintenance of the boiler you will need
the standard tools for central heating, gas and water fitting.
In addition, a handtruck with a fastening belt is very useful.
1.6 Inspection
We advise you to offer your customer an annual inspection and
maintenance contract. If inspection reveals that maintenance
work is necessary you can carry this out as required in the Instal-
lation instruction of the boiler.
Installation
– Periodically examine the venting systems and cleaning of the
screens in the vent terminal.
– Also periodically inspect the low water cutoffs, including
flushing of float types.
– And periodically inspect the burner flames (see page 8, fig. 1,
pos. 10).
– Check the neutralization unit if present.
– Check to see if there are no obstructions to the flow combus-
tion and ventilation air.
– For direct vent boilers, proper reassembly and resealing of
the vent-air intake system is required.
Maintenance
– Cleaning the heat exchanger, the burner and the condensate
trap (see installation instructions, Maintenance).
– Checking the ionization signal (par. 8.1.15, page 95)
– Checking and adjusting the gas/air ratio (par. 8.1.26,
page 108).
1.7 Disposal
– Dispose of the boiler packaging in an environmentally sound
manner.
– Dispose of components of the heating system
(e. g. boiler or control device), that must be replaced, by
handing them in to an authorized recycling facility.
– Keep boiler area clear and free from combustible materials,
gasoline and other flammable vapors and liquids.
DANGER
if flammable gas explodes.
Beware if you smell gas: there may be an
explosion hazard!
Warning: If the information in these instruc-
tions is not followed exactly, a fire or explo-
sion may result causing property damage,
personal injury or death.
-Do not store or use gasoline or other flam-
mable vapors and liquids in the vicinity of this
or any other boiler.
What to do if you smell gas
-Do not try to light any boiler.
-Do not touch any electrical switch; do not use
any phone in your building.
-Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
-If you cannot reach your gas supplier, call the
fire department.
Installation and service must be performed by a
qualified installer, service agency or the gas
supplier.
CAUTION:
– Check and clean the heating system at least
once a year.
– Carry out a maintenance overhaul if neces-
sary. Immediately repair defects to avoid
damage to the heating system!
Safety and general instructions1
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!6
1.8 Abbreviations
AM10 = Outdoor reset module
AS = System fault code
AV = Air Vent
BC = Operating code
BC10 = Control panel (on the boiler)
BCT = Boulter Buderus cylinder thermostat
BDV = Boulter Buderus diverter valve
BKS = Blocking boiler fault code
CB = Connection Block
CH = Central Heating
CHF = Central Heating Supply
CHR = Central Heating Return
CM10 = Cascade module
CT = Cylinder Thermostat
CWDO = Condensate water drainage outlet
CM10 = Cascade module
DHW = Domestic Hot Water
DV = Diverter Valve
E=Earth
EM10 = External control module
EMS = Energy management system
FA = Outdoor sensor
HK1 or HK2 = Central Heating line
KIM = Boiler identification module
L = Live Line
LED = Light Emitting Diode
LSV = Lock Shield Valve
MCW = Mains Cold Water
MM10 = Controler for HK2, second Central Heating line module.
N = Neutal
PE = Ground
PL = Permanent hot line
Prog = Programmer
RT or RC = Room Thermostat
SC = Service code
T=Timer
TRV = Thermostatic Radiator Valve
ÜC = Other display codes
UBA 3 = Universal automatic burner control unit 3
VKS = Locking boiler fault code
WC = Wiring Centre
WM10 = Controler for HK1, first Central Heating line
ZV = Two Port Zone Valve
Regulations and guidelines 2
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 7
2 Regulations and guidelines
The installation must conform to the requirements of the authority
having jurisdiction or, in the absence of such requirements, to the
latest edition of the National Fuel Gas Code, ANSI Z223.1. In
Canada, installation must be in accordance with the require-
ments of CAN/CSA B149.1, Natural Gas and Propane Installa-
tion Code.
Where required by the authority having jurisdiction, the installa-
tion must conform to the Standard for Controls and Safety
Devices for Automatically Fired Boilers, ANSI/ASME CSD-1.
Install CO detectors per local regulations. The boiler requires
yearly maintenance, see maintenance section see chapter
„8.1.27 Measuring the carbon monoxide content (CO)“ on
page 109.
Operating Limits of the boiler:
Max. boiler temperature: 220 °F (105 °C)
Max. operating pressure: 44 psi (3 bar)
The hot water distribution system must comply with all
applicable codes and regulations. When replacing an existing
boiler, it is important to check the condition of the entire hot water
distribution system to ensure safe operation.
Massachusetts Installations Only:
For direct- vent boilers, mechanical-vent heating boilers or
domestic hot water equipment, where the bottom of the vent
terminal and the intake is installed below four feet above grade
the following requirements must be satisfied:
1) If there is not one already present, a carbon monoxide
detector and alarm shall be placed in a living area outside
the bedrooms. The carbon monoxide detector and alarm
shall comply with NFPA 720 (2005 Edition).
2) A carbon Monoxide detector and alarm shall be located in
the room that houses the boiler or equipment and shall:
a) Be powered by in series on the same electrical circuit as
the boiler or equipment:
b) Have battery back-up power:
c) Meet ANSI/UL 2034 Standards and comply with
NFPA 720 (2005 Edition):
d) Have been approved and listed by a Nationally
Recognized Testing Lab:
3) A product-approved vent terminal must be used, and if
applicable, a Product approved air intake must be used.
Installation shall be in strict compliance with the
manufacturer's instructions. A copy of the installation.
4) A metal or plastic identification plate shall be mounted at the
exterior of the building, four feet directly above the location
of vent terminal. The plate shall be of sufficient size to be
easily read from a distance of eight feet away, and read "Gas
Vent Directly Below".
b) For direct-vent boilers mechanical-vent heating boilers
or domestic hot water equipment where the bottom of
the vent terminal and the intake is installed four feet or
above grade the following requirements must be
satisfied:
1) If there is not one already present, a carbon monoxide
detector and alarm shall be placed in the living area
outside the bedrooms, The carbon monoxide detector
and alarm shall comply with NFPA 720 (2005 Edition).
2) A carbon monoxide detector shall:
a) Be located inn the area where the boiler or
equipment is located:
b) Have battery back-up power:
c) Be a minimum comply with NFPA 720
(2005 Edition).
3) A product-approved vent terminal must be used, and if
applicable, a product-approved air intake must be used.
Installation shall be in strict compliance with the
manufacturer's instructions. A copy of the installation
instructions shall remain with the boiler or equipment at
the completion of the installation.
Product description3
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!8
3 Product description
1) ECO mode means that the temperature inside the hot water tank is 140 °F (60 °C), with a hysteresis (
Δ
T) of 18 °F instead of 9 °F
fig. 1 Logamax plus GB142-24/30 (left) and GB142-45/60 (right)
pos. 1: Drawer with control unit
pos. 2: Universal Burner Automat (UBA 3)
pos. 3: Control unit BC10
pos. 4: Gas valve
pos. 5: Cover
pos. 6: Flue measuring points
pos. 7: Parallel flue
pos. 8: Burner
pos. 9: Latches of which two have locks
pos. 10: Sighting glass
pos. 11: Heat exchanger
pos. 12: Back cover
pos. 13: Air intake for the fan
pos. 14: Fan
pos. 15: Condensate trap and internal condensate drain flue
gas pipe
pos. 16: External Connection Board (under the cover)
pos. 17: Pressure sensor
1
2
3
6
9
11
13
14
9
16
15
7
5
8
1
4
10
12
13
14
2
3
5
4
67
9
11
9
8
10
12
16
15 17
fig. 2 Basic Controller Logamatic BC10
pos. 1: Main switch
pos. 2: DHW temperature knob 1)
pos. 3: LED "DHW status"
pos. 4: Display
pos. 5: Space heating water temperature knob
pos. 6: LED "Heating system status"
pos. 7: Under the cover a RC system controller can be installed.
pos. 8: LED "Burner Operation"
pos. 9: Service Tool connector
pos. 10: "Service" e button
pos. 11: "Chimney sweep" d button
pos. 12: "Reset" c button
190
170
150
130
90
110
140
130
120
90
100
110
4
7
2
1
5
812 1011
3 6
9
Operation 4
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 9
4 Operation
4.1 Operating the BC10 basic controller
4.1.1 General
The boiler is equipped with an control unit, the basic controller
BC10. The BC10 allows you to operate the boiler.
-Briefly press on the control panel cover to open it
(see fig. 3).
The basic controller BC10 (see fig. 2) is located on the left side in
the drawer.
On the right side of the drawer there’s space for a RC control unit.
4.1.2 Switching the heating system on and off
Switching on the heating system
-Set the main switch on the BC10 basic controller to position "1"
(On).
Switching off the heating system
-Set the main switch on the BC10 basic controller to position "0"
(Off).
4.2 Menu structure of the BC10 basic controller
The menu structure of the boiler can be viewed on the BC10 using
the "Reset" c, "Chimney sweep d" and "Service e" (see
fig. 2, pos. 9, 10 and 11) buttons and the display indication (see
fig. 2, pos. 4).
The menu structure consists of 4 menus, schematically
represented on the following pages using structure diagrams:
– "Flue gas test" menu (page 10)
– "Service Mode" menu (page 11)
– "Manual Operation" menu (page 12)
– "Settings" menu (page 12).
fig. 3 Opening the control panel
Operation4
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!10
4.2.1 "Flue gas test" menu
"FLUE GAS TEST" MENU
no
yes
Press the service button.
psi
Current heating system pressure. See page 20.
Operating code. See page 21.
Activate
flue gas test?
Press the service button.
no
Activate flue gas test:
Press and hold the chimney sweep button
2 to 5 seconds.
The flue gas test is activated as soon as a dot is
visible in the lower right hand corner of the
display. This means that the boiler runs in
heating mode at 100 % for 30 minutes. The
maximum boiler water temperature as set on
the BC10 basic controller applies here.
A.
27 .
Press the service button.
Current supply temperature 0 ... 199 °F
(-18 .. 93 °C). See page 20.
2
7.
Deactivate
flue gas test?
Deactivate flue gas test:
Press and hold the chimney sweep button for
more than 2 seconds, until the decimal point
has disappeared.
yes
no
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27
yes
Have
30 min. passed or
was the power
interrupted?
9P2.
Operation 4
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 11
4.2.2 "Service Mode" menu
psi
Current heating system pressure. See page 20.
"SERVICE MODE" MENU
Activate service mode 2nd step:
Simultaneously press and hold the "Chimney
sweep" and "Service" buttons for more than
2 seconds.
Activate
service mode?
no
Activate service mode 1st step:
Press and hold the "Chimney sweep" button
for 2 to 5 seconds.
As soon as a non-flashing dot is shown in the
right-hand bottom corner of the display, the
boiler will run in heating mode at 100 % load for
30 minutes. The maximum boiler water
temperature set on the BC10 basic controller
applies.
27 .
Boiler load in line with "Settings" menu.
+
Current boiler load. See page 20.
Service mode activated.
You can now temporarily lower the boiler load
to partial load to check, and if relevant set the
gas/air ratio or the ionization current.
L.
Press and hold the "Reset" button until the
display shows "L30."
-
Press the "Service" button.
Press the "Service" button.
Current boiler load. See page 20.
The boiler will reduce its load to 30 % within a
couple of seconds. The maximum boiler water
temperature as set on the BC10 basic controller
applies. Check the gas/air ratio (see page 108)
or the ionization current (see page 95) and
adjust the gas/air ratio if necessary.
03L .
Have 30 min.
passed or was the
power interrupted?
Operating code. See page 46.
Press the "Service" button.
.
Press the "Service" button.
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27 .
Deactivate
service mode?
Deactivate service mode:
Press and hold the "Chimney sweep" button for
more than 2 seconds until the decimal point
has disappeared.
no
yes
yes
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
no
27 .
yes
9P2.
A
Operation4
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!12
4.2.3 "Manual Operation" menu
4.2.4 "Adjustments" menu
"MANUAL OPERATION" MENU
yes
Power
interrupted?
Press the "Service" button.
psi
Current heating system pressure. See page 20.
Operating code. See page 20.
During manual operation the "Adjustments"
menu on page 12 can be used to temporarily
change the required boiler load in case of an
emergency.
Activate manual
operation?
Press the "Service" button.
no
To activate manual operation:
Press and hold the "Chimney sweep" button for
more than 5 seconds.
As soon as a flashing dot is shown in the right-
hand bottom corner of the display, manual
operation is active. The means that the boiler is
permanently in heating mode. The maximum
boiler water temperature as set on the BC10
basic controller now applies. The "Heat
request" LED is lit.
Press the "Service" button.
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
Deactivate manual
operation?
no
2
7.
9P2.
27 .
Deactivate manual operation:
Press and hold the "Chimney sweep" button for
more than 2 seconds until the flashing decimal
point has disappeared.
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27
H.
no
yes
yes
Operation 4
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 13
"ADJUSTMENTS" MENU
Open programming mode: Simultaneously
press and hold the "Chimney sweep" and
"Service" buttons for more than 2 seconds.
Open the
“Adjustments” menu?
no
Boiler load and pump post purge
time settings confirmed.
+
As soon as the display shows "L--", the
programming mode is open. The first
parameter shown on the display is used to set
the boiler load for heating operation.
Adjust the boiler load with
the "Reset" button.
-
Press the "Service" button.
Have at least
5 min. passed without a button being
pressed or was the power supply
interrupted ?
As soon as the display shows "F ", the second
parameter can be set. This parameter
indicates the pump post purge time.
no
L
Adjust boiler load?
Adjust the boiler load with
the "Chimney sweep" button.
+
The setting "L30" means that the
heating load is lowered to 30 %.
„L__“ is the maximum
heating load setting of 100 %.
Factory default setting: "L " = 100 %.
03L L
yes, higher
yes, lower
5F
Adjust pump post
purge time?
"F00" is the minimum pump post purge time
setting in minutes. "F60" is the maximum
pump post purge time setting in minutes.
"F1d" is the maximum
pump post purge time setting for one day.
Factory default setting "F 5" = 5 minutes.
no
yes, higher
yes, lower
Adjust the pump post purge time with
the "Reset" button.
-
Adjust the pump post purge time with the
"Chimney sweep" button.
+
00F 1dF
Press the "Service" button.
yes
no
yes
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27
Function5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!14
5Function
5.1 General
To clarify the operation of the Logamax plus GB142-24/30/45/60
thermal power gas boilers under normal operating conditions, the
work steps are schematically represented in the structure diagrams
on the following pages of this chapter.
Function 5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 15
5.2 Structure diagram "Function"
1
Start up
Connect the heating system to the power grid
by turning the circuit breaker ON.
Turn the main switch on the BC10 to
position “1” (ON), see page 8, fig. 2.
A display check is carried out
(for max. 1 second).
888 ...
Flashes twice for 2 seconds until
communication between the UBA 3 and the
BC10 has been established.
Press the "Service" button.
Current heating system pressure.
See page 20.
Press the "Service" button.
Operating code.
The heating boiler is started.
U0
Is the
air purging phase
okay?
Unit will show an error code.
Fault must be fixed before
proceeding.
See chapter 6, 7 and 7.2.
no
2
yes
Current supply temperature 0 ... 199 °F
(-18 ... 93 °C). See page 20.
27
page 16
Start of air-side pre-flushing phase.
The blower runs for < 20 seconds at
approx. 60 % of the maximum speed.
The LED of the UBA 3 lights for 1 second.
This means that the UBA 3 is reading the
KIM. If a new KIM or UBA 3 has been
installed, the LED will flash at a high
frequency for max. 10 sec. while data is being
exchanged.
9P 2psi
Function5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!16
2
Has the pump post
purge time expired?
yes
yes
Have ten seconds
passed or was the power supply
interrupted?
yes
no
Operating code.
The boiler is in ready mode,
there is no heat request.
H
0
Start of pump post purge time via the heating
system. Pump post purge time in line with
"Settings" menu.
See page 12 and page 20.
Factory default setting: 5 minutes.
The primary circulation pump stops.
The primary circulation pump is run for
10 seconds to prevent it from seizing up.
no
page 15
3
page 17
no
Is
there a heat
request from the
room or outdoor
temperature-
dependent
regulator?
no
Is
the
temperature
in the hot water
tank at least
9 °F (5 K)lower than the
temperature set
on the BC10
or RC?
6
page 19
5
yes yes
no
3
page 17
Is
there a heat
request from the
room or outdoor
temperature-
dependent
regulator?
Is
the
temperature
in the hot water
tank at least
9 °F (5 K) lower than
the temperature set
on the BC10
or RC?
6
page 19
yes yes
no
3
page 17
Is
there a heat
request from the
room or outdoor
temperature-
dependent
regulator?
Is
the
temperature
in the hot water
tank at least
9 °F (5 K) lower than
the temperature set
on the BC10
or RC?
6
page 19
yes yes
no
no
no
page 18
Has the primary
circulation pump been off for
more than 24 hours?
Function 5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 17
4
7
page 18
3
yes
Is the temperature
in the hot water tank higher
than the hot water temperature setting
in the BC10 or RC control
device?
no
H
L0
C0
The blower is started up.
The tank filling pump
is activated.
The hot surface ignitor is activated
for seven seconds.
The primary circulation pump
is started.
Ignition phase:
The gas valve is opened.
GB142 is in the hot water mode.
The "Burner" LED is lit.
The "Hot water mode" LED on the
BC10 is lit.
The "Hot water mode" LED
goes off.
yes
no yes
no
page 16
The gas valve is closed,
the burner is shut down.
The "Burner" LED goes off.
The blower stops.
Is
the supply
temperature 82.8 K
higher than the hot water
temperature setting
or higher than
200 °F (93 °C)?
Is
the supply
temperature lower
than the preset
hot water temperature
plus 63 °F (35 K)?
page 19
Y0
Function5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!18
5
Is there a
heat request from the room or
outdoor temperature-dependent
regulator?
yes
4
page 18
A0
The gas valve is closed,
the burner is shut down.
The "Burner" LED goes off.
Start the pump over-run time through the hot
water tank at least 30 seconds,
max. 1 minute, if there is a heat request.
Air-side after-purging by blower
for 30 seconds.
The blower stops.
The primary circulation pump stops.
The tank filling pump
is stopped.
no
6
page 19
page 16
H0
Function 5
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 19
Is the
temperature in the hot water
at least 9 °F (5 K) lower than the temperature
set on the BC10 or RC?
6
Is the
room or outdoor temperature-
dependent regulator in the request
position?
no
yes
The GB142 enters heating mode.
The "Burner" LED is lit.
H
The "Heat request" LED goes off.
Is
the supply
temperature
11 °F (6 K) higher than
the target value? (The target value
is calculated by the outdoor
temperature-dependent regulator
or is set - in the event of room
temperature-dependent
regulation- on the
BC10)
5
H0
The gas valve is closed,
the burner is shut down.
The "Burner" LED goes off.
Start of pump post purge time via the heating
system. Pump post purge time in line with
"Settings" menu. See page 12 and page 20.
Factory default setting: 5 minutes.
Air-side after-purging by blower for
30 seconds.
The primary circulation pump stops.
page 16
The blower stops.
page 17
7
yes no
The gas valve is closed,
the burner is shut down.
The "Burner" LED goes off.
The blower stops.
Is
the supply
temperature 11 °F (6 K)
lower than the
target value?
no yes
L0
C0
The blower is started up.
The hot surface ignitor is activated for
seven seconds.
The circulation pump is started up.
Ignition phase:
The gas valve is opened.
The "Heat request" LED is lit.
page 16, page 18
Yes
no
Y0
Symptoms6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!20
6 Symptoms
6.1 Display indication on the BC10 basic controller
6.1.1 General
A display value or code is shown on the display of the BC 10 basic controller (see page 8, fig. 2).
6.1.2 Display values on the display of the BC10 basic controller
The display value is shown automatically or can be called up by pressing the "Chimney sweep d" or "Service e" button (see
page 10 and 12.
The following display values can be shown on the display of the BC10 basic controller:
6.1.3 Display codes on the display of the BC10 basic
controller
A display code shows the current status of the Logamax plus
GB142.
The display value is shown automatically or can be called up by
pressing the "Service e" button.
Two display codes (see table 2 level 3 and level 4) are shown.
After the first display code (level 3) is displayed, the second one
(level 4) can be called up by pushing the “Service e“ button. On
the BC10 basic controller level 4 can only be called up in the event
of a fault code.
Under normal operating conditions it is only possible to call up level
4 using the RC control device or a service tool.
Display
value Type of display value Unit Range
Factory
default
setting
[\/7/2| Current supply temperature °F [\/\/0| –[l/9/9| 1) /
°C [-/1/8| –[\/9/3|
[p/2/9| Current heating system pressure psi [p/0/0| –[p/2/9| /
[l/9/9| Configured target load % [l/3/0| –[l/9/9| /[l/?/?| [l/?/?|
[f/\/5| Configured target pump post purge time min [f/0/0| –[f/6/0| /[f/1/d| [f/\/5|
table 1 Display values on the BC10 basic controller
If the display code is a fault code, this fault code either flashes
(locked fault code) in the display or it is shown permanently
(blocking fault code). A boiler reset is only necessary with a
locking fault code (flashing) (see 8, fig. 2). The cause of the
fault must be remedied first. The cause has to be remedied
and the boiler resumes regular operation.
In the event of a locking boiler fault code both the display
value and the display code flash.
If there are more than once display codes at the same time,
the display codes will be shown in turn. And if one of these
display codes is a locking display code, the blocking display
codes shown will also flash.
Symptoms 6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 21
The following display values can be shown on the display of
the BC10 basic controller:
Abbreviations used in table 2:
Type of display code:
BC - Operating code
SC – Service code
BKS – Blocking boiler fault code
VKS – Locking boiler fault code (flashing)
AS – System fault code
ÜC – Other display codes
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
[\/\/\| [\/\/\| No indication in
display.
page 28 page 28
[\/-/\| Communication test while starting up.
This code flashes 2 x 2 seconds while
starting up to indicate that the
communication between the UBA 3 and
the BC10 basic controller is being tested.
If a new UBA 3 or a new KIM was fitted,
this code will flash for
max. 10 seconds. If this code continues
to flash on the display, there is a fault in
the communication between the UBA 3
and the BC10 basic controller.
See page 46.
This fault code will also appear when
connecting a thermostat to the RC
terminals.
ÜC No heating
operation and no
hot water.
e[-/a/\]
or any other
indication
with a
permanent
dot in the
bottom
right-hand
corner.
[2/0/8|
1)
The boiler is in the flue gas test mode or
in service mode.
BC page 10 or
page 11
page 10 or page 11
e[-/h/\| e[2/0/0|
1)
The boiler is in heating mode. BC
e[-/h/}
any other
indication
with a
flashing dot
in the
bottom
right-hand
corner.
e[2/0/0|
1)
The boiler is in manual operation mode. BC The room
temperature is too
high.
page 12 page 12
e[=/h/\| e[2/0/1|
1)
The boiler is in hot water mode. BC
e[0/a/\| e[3/0/5|
1)
The boiler has switched off. Start the
pump over-run time via the tank for at
least 30 seconds and maximum
1 minute.
BC
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
Symptoms6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!22
e[0/a/\| e[2/0/2|
1)
Operating phase:
The switch optimization program is
activated.
This program is activated if there is more
than one burner firing requests from an
RC or ON/OFF regulator within 10
minutes.
This means that the boiler cannot be
restarted until at least ten minutes have
elapsed since initial startup of the burner.
BC Possibly no
heating operation.
e[0/c/\| e[2/8/3|
1)
The burner is started. BC
e[0/e/\| e[2/6/5|
1)
Readiness for operation:
The boiler is in ready mode.
The time-proportional program is
activated.
The time-proportional program is
activated as soon the load requested by
the modulating room controller is lower
than the lower limit of the boiler load.
During the time-proportional program the
burner is switched on and off repeatedly.
The period in which the burner is
switched on depends on the difference
between the load required by the
modulating room controller and the lower
limit of the boiler load. As soon as the
burner is switched on, the device is
operating at minimum load. As soon as
the burner is switched off, the display
code [0/e/\| e [2/6/5| is indicated in the
display of the BC10.
The time-proportional program is
deactivated automatically as soon as the
load required by the modulating room
controller is higher than the lower limit of
the boiler load.
BC
e[0/h/\| e[2/0/3|
1)
The boiler is in ready mode, there is no
heat request.
BC
e[0/l/\| e[2/8/4|
1)
The gas valve is opened. BC
e[0/u/\| e[2/7/0|
1)
Power Up.
Boiler is starting up after a reset or after
the main power is switched on.
This display code will be displayed for 4
minutes maximum.
BC
e[0/y/\| e[2/0/4|
1)
The boiler switches off, the temperature
is higher than the target temperature.
BC
e[0/y/\| e[2/7/6| eThe supply sensor has measured
a temperature higher than 203 °F
(95 °C).
BKS no
e[0/y/\| e[2/7/7| eThe safety sensor has measured
a temperature higher than
203 °F (95 °C).
BKS no
e[0/y/\| e[2/8/5| eThe return sensor has measured
a temperature higher than
203 °F (95 °C).
BKS no
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
Symptoms 6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 23
e[1/c/\| e[2/1/0| eFlue gas sensor is activated
(not available).
BKS no Flue gas sensor
has measured a
flue gas tempe-
rature higher than
221 °F (105 °C)
e[1/l/\| e[2/1/1| eThe UBA 3 does not register any
connections to the unused contacts 78
and 50.
BKS no No heating
operation and no
hot water.
page 48 page 48
e[2/e/\| e[2/0/7| eThe system pressure is too low. BKS no No heating
operation and no
hot water.
page 48 page 48
e[2/f/\| e[2/6/0|
1)
No temperature increase after burner
start or the temperature difference
between the supply and safety sensors is
more than 27 °F (15 K).
BC page 49 page 49
e[2/f/\| e[2/7/1| eThe temperature difference between the
supply and safety sensors is more than
27 °F (15 K).
BKS no page 49 page 49
e[2/l/\| e[2/6/6| eThe primary circulation pump does not
generate a pressure difference.
VKS yes No heating
operation and
no hot water.
page 50 page 50
e[2/p/\| e[2/1/2|
1)
Temperature increase of supply sensor
or safety sensor is more than 9 °F/sec
(5 K/sec).
BC page 52 page 52
e[2/u/\| e[2/1/3|
1)
The temperature difference between the
supply and return sensors is more than
90 °F (50 K).
BC page 53 page 53
e[3/a/\| e[2/6/4| eThe air flow by the blower has failed
during the operating phase.
BKS no page 54 page 54
e[3/f/\| e[2/7/3| eThe blower is switched off during the
safety test.
BKS no page 55 page 55
e[3/l/\| e[2/1/4| eThe blower is switched off during the
safety test.
VKS yes No heating
operation and
no hot water.
page 56 page 56
e[3/p/\| e[2/1/6| eThe blower is running too slowly. VKS yes No heating
operation and
no hot water.
page 57 page 57
e[3/y/\| e[2/1/5| eThe blower is running too fast. VKS yes No heating
operation and
no hot water.
page 58 page 58
e[4/a/\| e[2/1/8| eThe supply sensor has measured a
temperature higher than 221 °F (105 °C).
VKS yes No heating
operation and
no hot water.
page 59 page 59
e[4/c/\| e[2/2/4| eThe UBA 3 does not register the short cut
bestween the unused contacts 22 and
24.
VKS yes No heating
operation and
no hot water.
page 60 page 60
e[4/e/\| e[2/7/8| eThe sensor test has failed. VKS yes No heating
operation and
no hot water.
page 60 page 60
e[4/l/\| e[2/2/0| eThe safety sensor is shorted or
measures temperatures higher than 266
°F (130 °C).
VKS yes No heating
operation and
no hot water.
page 61 page 61
e[4/p/\| e[2/2/1| eThe safety sensor contact
is interrupted.
VKS yes No heating
operation and
no hot water.
page 62 page 62
e[4/u/\| e[2/2/2| eThe supply sensor is shorted. VKS yes No heating
operation and no
hot water.
page 63 page 63
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
Symptoms6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!24
e[4/y/\| e[2/2/3| eThe supply sensor contact is interrupted. VKS yes No heating
operation and
no hot water.
page 64 page 64
e[6/a/\| e[2/2/7| eNo ionization after ignition.
After four startup attempts, a locking
boiler fault follows [6/a/\|.
BKS no page 65 page 65
e[6/a/\| e[2/2/7| eNo ionization after four startup attempts. VKS yes No heating
operation and
no hot water.
page 65 page 65
e[6/c/\| e[2/2/8| eAn ionization current was measured
before the burner start.
VKS yes No heating
operation and
no hot water.
page 72 page 72
e[6/c/\| e[3/0/6| eAn ionization current was measured after
the burner switch-off.
VKS yes No heating
operation and
no hot water.
page 72 page 72
e[6/l/\| e[2/2/9| eIonization fails during the operating
phase.
BKS no page 73 page 73
e[6/p/\| e[2/6/9| eThe hot surface ignitor activates too long. VKS yes No heating
operation and
no hot water.
page 78 page 78
e[7/c/\| e[2/3/1| eThe power supply was interrupted and
switched on again after a fault message.
VKS yes No heating
operation and
no hot water.
page 78 page 78
e[7/l/\| e[2/6/1| eThe UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 78 page 78
e[7/l/\| e[2/8/0| eThe UBA 3 is defective. VKS yes
e[8/y/\| e[2/3/2|
1)
The external switch contact is activated. BC page 79 page 79
[8.8.8] Display test while starting up. This code
is displayed for a maximum of 1 second.
ÜC
e[9/a/\| e[2/3/5| eKIM or UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 80 page 80
e[9/h/\| e[2/3/7| eKIM or UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 80 page 80
e[9/h/\| e[2/6/7| eThe UBA 3 is defective. VKS yes No heating
operation and
no hot water.
e[9/h/\| e[2/7/2| eThe UBA 3 is defective. VKS yes No heating
operation and
no hot water.
e[9/l/\| e[2/3/4| eThe gas valve coil or the wiring to the gas
valve is defective.
VKS yes No heating
operation and
no hot water.
page 81 page 81
e[9/l/\| e[2/3/8| eThe UBA 3 is defective. VKS yes
e[9/p/\| e[2/3/9| eKIM or UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 80 page 80
e[9/u/\| e[2/3/3| eKIM or UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 80 page 80
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
Symptoms 6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 25
e[a/0/1| e[8/0/0| eOutdoor sensor AS The minimum
outdoor
temperature is
assumed.
Sensor
connected or
fitted incorrectly.
Check the sensor
connection and the
sensor wire.
Sensor wire
broken or
shorted.
Check the sensor
installation.
The sensor is
defective.
Compare the
resistance value to
the sensor graph.
e[a/0/1| e[8/0/8| eHot water temperature sensor AS No water is
heated any more.
Sensor
connected or
fitted incorrectly.
Check the sensor
connection and the
sensor wire.
e[a/0/1| e[8/0/9| eHot water temperature sensor 2
Sensor wire
broken or
shorted.
Check the sensor
installation on the
hot water tank.
The sensor is
defective.
Compare the
resistance value to
the sensor graph.
e[a/0/1| e[8/1/0| eHot water remains cold. AS The system
constantly tries to
heat the hot water
tank to the hot
water target value
setting.
The hot water
priority is
cancelled when
the fault message
appears.
Permanent
tapping or leak.
Remedy the leak if
relevant.
Sensor
connected or
fitted incorrectly.
Check the sensor
connection and the
sensor wire.
Sensor wire
broken or
shorted.
Check the sensor
installation on the
hot water tank.
The sensor is
defective.
Compare the
resistance value to
the sensor graph.
Fill pump
connected
incorrectly or
defective.
Test the fill pump
operation e. g.
using a relay test.
e[a/0/1| e[8/1/1| eThermal disinfection. AS Thermal
disinfection was
interrupted.
Tap flow rate too
great during
disinfection
period.
Choose the time for
thermal disinfection
so that no
additional heat
request occurs at
this time.
Boiler load too
low for
simultaneous
heat use by
other connected
loads (e. g. 2nd
heating circuit).
Sensor
connected or
fitted incorrectly.
Check the sensor
connection and the
sensor wire.
Sensor wire
broken or
shorted.
Check the sensor
installation on the
hot water tank.
The sensor is
defective.
Compare the
resistance value to
the sensor graph.
Fill pump
defective
Test the fill pump
operation e. g.
using a relay test.
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
Symptoms6
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!26
6.2 LED on the UBA 3
In addition to the display indication on the BC10 basic controller, there is a red LED on the UBA 3.
The meaning of this LED is explained in see table 3.
e[a/0/1| e[8/1/6| eNo communication with EMS. AS The boiler no
longer gets heat
requests; the
heating system no
longer heats.
EMS bus system
is overloaded.
Reset by switching
the heating system
on and off.
Inform the
BUDERUS
customer service
department if
necessary.
UBA 3/MC10 is
defective.
e[a/0/1| e[8/2/8| eWater pressure sensor. AS The digital water
pressure sensor
is defective.
Replace the digital
water pressure
sensor.
e[a/0/2| e[8/1/6| eNo communication with BC10. AS BC10 settings are
no longer taken
over by RCxx
devices.
Contact problem
at BC10 or BC10
is defective.
Check the BC10
connection.
Replace the BC10
if necessary.
e[c/0/\| e[2/8/8| eThe UBA 3 has no connection to the
pressure sensor or there is a short circuit.
VKS yes No heating
operation and no
hot water.
page 82 page 82
e[c/0/\| e[2/8/9| eShort circuit in connection to pressure
sensor.
e[c/a/\| e[2/8/6| eThe return sensor has measured a
temperature higher than 221 °F (105 °C).
VKS yes
e[c/u/\| e[2/4/0| eThe return sensor is shorted. VKS yes
e[c/y/\| e[2/4/1| eThe return sensor contact is interrupted. VKS yes
e[e/\/\|
+ any digit
or letter
e[2/9/0| eThe UBA 3 is defective. BKS no No heating
operation and
no hot water.
page 80 page 80
e[e/\/\|
+ any digit
or letter
e[2/4/2|
to
[2/8/7|
eKIM or UBA 3 is defective. VKS yes No heating
operation and
no hot water.
page 80 page 80
[h/\/7| The heating system pressure is too low. SC page 78 page 80
e[h/\/7| eThe heating system pressure is too low. SC page 78 page 80
[r/e/\| Reset is carried out. After pressing the
"Reset" button this code is displayed for
5 seconds.
ÜC 2)
Symptoms
Diagnosis Remedy
Display code
Key to display code
Type of
display
code
Reset
required
?
Other
symptoms
zMain
display
code zSub-
display
code z
table 2 Display indications on the BC10 basic controller
1) only visible using the service tool
2) is being carried out
LED Meaning
Off Normal operation
Flashing slowly (1 Hz) There is a boiler fault (locking fault).
Flashing fast (10 seconds) During startup after replacing the KIM or the UBA 3.
On During a fault in the UBA 3 or if the KIM is not recognized.
table 3 LED on the UBA 3
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 27
7 Diagnosis
7.1 Faults without a fault code
Hot water request
Although the UBA 3 indicates that the system is ready for
operation, it is possible that in the event of a hot water request no
hot water is made available, or it is only made available for a short
time.
Structure diagram for troubleshooting, see page 33.
Heating mode
Although the UBA 3 shows that the system is ready for operation
and the room temperature has not reached the preset value, the
Logamax plus GB142 does not enter the heating mode.
Structure diagram for troubleshooting: page 44.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!28
No display
8
page 31
yes
no
no
no
yes
Is the mains power
switch ON?
No indication in display.
no
yes
7
page 30
Switch on the mains power switch.
Check that the operating switch is in
position “1” (ON). See page 9.
yes
no
Is the
operating switch on the BC 10 in
position “1” (ON)?
Turn the operating switch on the BC 10 to
position “1” (ON). See page 9 (fig. 2).
Is the 120V AC cord okay?
Check that there is a 120V AC power
supply at the mains power switch.
yes
Is there a voltage at the
mains power switch?
Measure the resistance of the 120V AC
supply cord.
Check the fuse on the rear of the UBA 3
using a volt-ohm-multimeter.
See page 84.
Is the fuse okay? 44
page 83
Is there any indication on the
BC10 display?
Replace the fuse.
See page 84.
Deal with any problem in the electrical
system.
yes
no
Replace the cable loom (or the affected
part thereof.
Check that the mains power switch
is ON.
No
yes
Do the other
functions of the device work
normally?
19
page 29
Turn the operating switch on the BC10 to
position “0” (OFF). See page 9, par. 4.2.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 29
44
page 83
Measure the relevant part of the cable loom.
See page 126.
Yes
Is the cable loom okay?
8
page 31
Check that there is between 7.8 and 15.2
VDC on both contacts 1 and 2 of the BC10.
See page 126.
No
No
Is there a voltage?
19
page 28
Replace the BC10.
See the fitting instructions of
the BC10.
Yes
Replace the cable loom or the
affected part thereof.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!30
No display, part 2
Replace the fuse again.
See page 84.
No
No
Yes
7
Disconnect the following boiler components
from the electrical power supply:
- the blower, see page 86,
- the primary circulation pump,
see page 126.
No
Yes
Is the fuse okay?
Is there any indication on the
BC10 display?
Connect the external primary
circulation pump.
10
page 31
Turn the operating switch on the BC 10 to
position “1” (ON). See page 9, par. 4.2.
Turn the operating switch
to “0” (OFF).
Is there any indication on the
BC10 display?
Turn the operating switch on the BC10 to
position “1” (ON). See page 9, par. 4.2.
Replace the external primary
circulation pump.
Replace the fuse again.
See page 84.
9
page 32
Check the fuse on the rear of the UBA 3
again using a volt-ohm-multimeter.
See page 84.
Yes
page 28
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 31
No displa y, part 3
No
10
8
Yes
Turn the operating switch on the BC10 to
position “0” (OFF). See page 9, par. 4.2.
Connect the blower. See page 86.
Is there any indication on the
BC10 display?
Replace the blower.
See page 88.
Replace the fuse again.
See page 84.
Turn the operating switch on the BC10 to
position “1” (ON). See page 9, par. 4.2.
8
Logamax plus
GB142-15/24/30/45/60 okay.
Turn the operating switch on the BC10 to
position “0” (OFF). See page 9, par. 4.2.
Turn the operating switch on the BC10 to
position “1” (ON). See page 9, par. 4.2.
Fit the casing.
Make the heating system ready
for operation.
page 31
page 30
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!32
No display, part 4No display, part 5
8
page 31
9
page 30
Are the wires okay? No
Yes
Replace the supply cord of the transformer
and replace the fuse again.
See page 84.
Use a volt-ohm-multimeter to check the
supply wires of the primary circulation pump,
the blower and the hot surface ignitor for signs
of short circuiting.
See page 87 and page 93.
44
page 83
Replace the cable loom or the affected part
thereof and the fuse again.
See page 84.
Use a volt-ohm-multimeter to measure
contacts L and N of the transformer for
resistance.
Is the resistance approx. 50 Ohms?
Measure the supply cord of the transformer to
make sure it is not broken or shorted.
Is the supply cord okay?
Yes
No
No
Yes
Replace the transformer,
see page 109.
And replace the fuse again.
See page 84.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 33
Hot water mode not operational; heating mode is operational
On devices with
external hot water tanks.
No hot water but heating is operational,
possibly radiators become hot without
there being a heat request.
No
No
No
Yes
Check that the hot water outlet conduit
immediately under the hot water tank
becomes hot and that the settings on the
RC device are correct.
Turn the operating switch on the BC10 to
position “0” (OFF) and turn the operating
switch to "1" (ON).
Open hot water tap.
Are the settings okay?
Check:
- that the hot water supply has been registered with
the control device. See the Operating instructions
of the BC10 and the RC control device.
- that the hot water target value setting is high
enough (140 °F = 60 °C). See page 8, fig 2.
- that the hot water supply is not switched off by the
timer program of the RC control device. See the
Operating Instructions of the RC control device.
Check that the "Hot water mode" LED
on the BC10 is lit.
See page 8, fig 2.
Does this conduit warm up
to approx. 140 °F (60 °C)?
Adjust the settings.
11
page 34
12
page 35
Is the LED lit?
Yes
8
page 31
Yes
13
page 34
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!34
Not hot water, branch 001
Not hot water, branch 002
Not hot water, branch 003
11
page 33
Check that the cold water inlet and hot water
outlet conduit connections on the hot water
tank are not reversed.
Are such items detected?
The cause of the fault is to be found outside
the device and the hot water tank.
Yes
No
Are the water-side
conduits connected properly?
No
Yes
Connect the conduits correctly.
Close the shut-off valve in the cold-water inlet
and open a hot water tap at random to see if
water comes out of it.
Is this the case? Yes
No
The cause is then a defective mixer tap, a
thermostat-controlled mixer valve or a short
circuit between the hot- and cold-water
conduit circuits.
Place the affected components out of service.
Check to see if any other external part of the
heating circuit is a possible cause.
44
page 83
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 35
Repl. AA
No
12
page 33
Yes
Is the hot water
temperature sensor okay?
Check the hot water temperature sensor.
See page 89.
Replace the hot water temperature sensor.
See page 91.
Is the wire okay?
Check the wire of the hot water temperature
sensor between the terminal strip and the
UBA 3 mounting base using a continuity
checking device. See page 92.
No
Yes
44
page 83
Replace the cable loom or the affected part
thereof.
8
page 31
13
page 33
Does the burner in the
boiler activate?
Check that the burner in the boiler activates
as specified in the structural diagram,
page 17.
No
Yes
Remedy the fault using the structure diagram
that corresponds with the fault code.
Yes
15
page 39
Is a tank filling pump fitted? No 21
page 36
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!36
Repl. BB
No
Check the cable loom of the device.
21
page 34
Check that during hot water mode there is a
120V AC voltage on the tank filling pump.
Does
the connection board
have on both contacts L and N of
connection PS 120V AC during hot
water operation?
Is the tank filling
pump running?
Check that the tank filling pump
is running.
No
Yes
44
page 83
Is the tank filling pump
being activated?
Check the connection board to make sure that
there is 120V AC on both contacts L and N of
connection PS (gray) during hot water mode.
Check the fuse on the connection board.
Value: 5A. See page 84.
Is the fuse
on the connection board
okay?
Yes
No
Yes
Yes
No
No
Yes
Replace the supply
cord of the tank-filling
pump.
Replace the fuse on
the connection board.
See page 84.
Replace the cable
loom.
8
page 31
46
page 37
45
page 37
Is the tank filling pump
running?
No
Yes
Is the cable loom okay?
Replace the circuit board.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 37
45
Check the tank-filling pump for soiling or for
a defective pump impeller wheel.
Replace or clean the tank filling
pump.
Yes
The external hot water tank is furred up.
Decalcify the tank.
No
8
page 31
Check that the pump impeller wheel of the
tank filling pump is not blocked.
Is the
pump impeller wheel of the tank filling
pump blocked?
Yes
46
page 36
page 36
8
page 31
47
page 37
Is the
tank-filling pump soiled or is the pump
impeller wheel defective?
As described for the primary circulation
pump, the tank filling pump must be turned in
the direction of rotation of the pump using a
screwdriver.
No
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!38
47
page 36
Replace the tank filling
pump.
No
Replace the
capacitor.
8
page 31
Check that the capacitor of the
tank filling pump is okay.
Is the
capacitor of the tank filling pump
okay?
Yes
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 39
No
Measure the inlet gas pressure (flow
pressure). See page 107.
Is the inlet gas pressure
okay?
15
page 34
Check the following elements for soiling and/
or damage:
- the combustion-air inlet conduit
- the air suction tube,
- the gas orifice, see page 101
- the blower, see page 86
- the connection between the blower and the
burner
- the burner
- the heat exchanger, see page 117
- the flue gas conduit.
Are the above-
mentioned components clean and
free from damage?
Yes
Yes
Is there
corrosion or scale inside the primary
circulation pump?
Clean the primary
circulation pump (inside).
Check the primary circulation pump for
corrosion or scale.
No
No
Yes
Clean and/or replace the corresponding
components.
16
page 40
If the required inlet gas pressure is not
available, you should consult the relevant
gas utility company.
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!40
Repl. CC
16
page 39
Is the gas/air ratio
okay?
Check the gas/air ratio.
See page 108.
No
Yes
Yes
No
Is the hot water tank
scaled up?
Yes
No
Check to see if any other external part
of the heating circuit is a possible cause of
the fault.
44
page 83
Check the hot water tank
for scale build-up.
Decalcify the tank.
Are such items detected? Place the affected components out of service.
8
page 31
Adjust the gas/air ratio.
See page 108.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 41
hot water but no central heating
On devices with
external hot water tanks.
hot water available,
no heating operation.
No
Yes
Yes
No Increase the temperature setting on the RC
control device. See the Operating Instructions
of the RC control device.
Check that the RC control device settings are
correct. See the Operating Instructions of the
RC control device.
Check that the boiler water temperature
setting on the BC10 (see page 9) or the
RC control device is high enough.
Yes
No
Are the RC control
device settings correct?
Increase the boiler water temperature setting
on the BC10 (see page 9) or on the
RC control device.
Increase the boiler load setting.
See "Adjustments" menu on page 12.
Check that the boiler load setting is correct.
See "Adjustments" menu on page 12.
Is the boiler load setting high
enough?
Check that the "Heating request" LED on the
BC10 is lit. See fig. 2, page 8.
Is the "Heating request"
LED lit?
No Check the control device. See page 104.
Yes
Is the boiler water temperature set-
ting high enough?
8
page 31
Yes
44
page 83
Is a
hot water tank connected? 44
page 83
No
Yes
Is a
tank pump fitted? 20
page 42
No
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!42
Hot water but no cen tral heating contin ued -2
Check the cable loom of
the device.
Is the cable loom
okay?
20
page 41
Check that during heating mode there is a
120V AC voltage on the DHW circulation
pump.
Is
there a voltage?
Is the
DHW circulation pump running?
Check that the DHW circulation pump is
running, as described for the primary
circulation pump.
No
Yes
44
page 83
Is there a
voltage?
Check the connection board to make sure that
there is 120V AC on both contacts L and N
of connection PS (green) during heating
mode.
Yes
No
Yes
No
Yes
Replace the
cable loom.
No
Replace the connection board.
Is the DHW circulation
pump running?
No
Yes
8
page 31
Replace the supply cord of
the tank-filling pump.
49
page 43
48
page 43
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 43
48
8
page 31
page 36
The fault is caused by the
system and not by the
boiler.
No
49
page 36
Check that the pump impeller wheel is
not blocked.
As described for the primary circulation
pump, the DHW circulation pump must be
turned in the direction of rotation of the
pump using a screwdriver.
Is the
pump impeller wheel
blocked?
Yes
50
No
8
page 31
Check the DHW circulation pump for soiling or
for a defective pump impeller wheel.
Is the
DHW circulation pump soiled or is
the pump impeller wheel
defective?
Yes
Clean or replace or the DHW circulation
pump.
page 43
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!44
Hot water but no cen tral heating contin ued -3
no central heating
50
page 36
Check that the capacitor of the DHW
circulation pump is okay.
Replace the DHW circulation pump.
Is the
capacitor of the DHW circulation
pump okay?
Yes
No Replace the capacitor.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 45
No digital pressure display
8
page 29
Yes
No
Yes
Is the plug-and-socket
connection okay?
44
page 83
Reconnect the plug-and-socket connection of
the pressure sensor.
See page 8, fig. 1, pos. 17.
Check the wires between the pressure sensor
plug and the UBA 3 mounting base, by using
a proper measuring device.
See page 126, fig 110.
Yes
No
Is the wiring
okay?
Replace the cable loom or the affected
part thereof.
Replace the pressure sensor to test whether
the fault can be traced back to the sensor.
See page 116, paragraph 8.1.33.
Check that the cable plug from the pressure
sensor is connected.
See page 8, fig. 1, pos. 17.
Can a pressure
indication be read out on the
display?
No
No digital system water pressure indication on
the display of the BC10 basic controller.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!46
7.2 Faults with a fault code
The following structural diagrams can be used for the systematic
troubleshooting of faults with fault codes.
While trying to establishes the fault causes, you should always also
check the contacts of all electrical plug-and-socket connections
and the connection plugs in the UBA 3.
Whenever a fault has been remedied, you must press the "Reset"
button (for at least 5 seconds) to reset the UBA 3 to its setting
status (release).
If a fault is displayed again, you should follow the relevant structural
diagram to carry out further troubleshooting.
Certain trouble-shooting activities have to be carried out in the
heating mode of the Logamax plus GB142. The flue gas test or the
service mode must be activated then, see chapter „4 Operation“ on
page 9, "Flue gas test" menu on page 10 and "Service Mode"
menu on page 11.
Locking boiler-fault code - (dash)
Operating code -A
WARNING!
Danger to life due to electric shock.
-Switch off the Logamax plus GB142 when
testing the connections!
NOTE!
Resetting is not possible by switching off the
operating switch!
New
fault message
?
No
Yes
page 83
Press the "Reset" button.
8
page 31
No communication between UBA 3 and
BC10. Other display code.
44
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 47
L
o
c
k
i
n
g
b
o
il
e
r
-
f
a
u
lt
c
o
d
e
1
L
(
fl
a
s
h
i
n
g
)
B
l
o
c
k
i
n
g
b
o
il
e
r
-
f
a
u
lt
c
o
The supply sensor has measured a
temperature higher than 203 °F (95 °C). Locking boiler-fault code.
The safety sensor has measured a
temperature higher than 203 °F (95 °C). Locking boiler-fault code.
The return sensor has measured a
temperature higher than 203 °F (95 °C). Locking boiler-fault code.
0Y
276
0Y
277
0Y
285
Wait approx. 60 seconds until the boiler
automatically becomes operational again.
fault message ?
0Y
Check the supply, safety and return sensors
(page 89).
Are all servicing cocks
open?
Is the
system pressure (measured on the boiler)
in the heating system at least
14.5 psi (1 bar)?
Are the supply and safety
sensors okay?
Is at least
one thermostatic valve open?
Is the primary circulation
pump okay?
page 83
Yes
Yes
Yes
Yes
Yes
Yes
Open the servicing cocks.
Fill and bleed the heating system.
Replace the supply, safety and/or return
sensors (page 91).
Open a thermostatic valve.
Replace the primary
circulation pump.
No
No
No
No
No
No
44
Check the primary
circulation pump.
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!48
de 2E
Operating code 2F
Replace the pressure sensor to test whether
the fault can be traced back to the sensor.
See page 116.
Is the pressure
in the heating system at least
14.5 psi (1 bar)?
page 83
Yes
Yes
Fill and bleed the heating system.
No
44
Is the
blocking boiler-fault code
cleared from the display?
No
8
page 31
The UBA 3 does not register any connections
to the unused contacts 78 and 50. Locking boiler-fault code.
1L
21 1
Check the contact between the UBA 3
and the UBA 3 mounting base.
See page 125, fig 109.
Is the contact
okay?
Has the malfunction been repaired?
Yes
Yes
Restore the contact between the UBA 3 and
the UBA 3 mounting base.
See page 125, fig 109.
No
No
page 83
44
Try to remedy the fault by replacing the entire
cable loom.
8
page 31
The system pressure is too low. Locking boiler-fault code.
2E
207
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 49
Blocking boiler-fault code 2F
Wait approx. 60 seconds until the boiler
automatically becomes operational again.
fault message ?
F2
Check the supply and safety sensors
(page 89).
Are all servicing cocks
open?
Is the
system pressure (measured on the boiler)
in the heating system at least
14.5 psi (1 bar)?
Are the supply and safety
sensors okay?
Is at least
one thermostatic valve open?
Is the primary circulation
pump okay?
page 83
Yes
Yes
Yes
Yes
Yes
Yes
Open the servicing cocks.
Fill and bleed the heating system.
Replace the supply and/or safety sensors
(page 91).
Open a thermostatic valve.
Replace the primary
circulation pump.
No
No
No
No
No
No
44
Check the primary
circulation pump.
8
page 31
No temperature increase after burner start or
the temperature difference between the supply
and safety sensors is more than 27 °F (15 K).
Operating code
The temperature difference between the supply
and safety sensors is more than 27 °F (15 K). Locking boiler-fault code.
2F
260
2F
271
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!50
Locking boiler fault code 2L
Is the primary circulation pump
jammed?
Does the primary circulation
pump run during ?
L2
Yes
Yes
No
No
Check the primary circulation pump for
mechanical jamming.
Check the primary circulation pump
activation.
Is the supply cord okay?
Try to undo the jam or replace the primary
circulation pump.
Is the activation okay?
page 83
44
22
page 51
Check the primary circulation pump; check
that the supply cord is not broken.
Replace the primary circulation pump.
Replace the supply cord.
Yes
Yes
No
No
8
page 31
The primary circulation pump does not
generate a pressure difference. Locking boiler-fault code.
L2
662
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 51
Locking boiler fault code 2L TT
22
page 50
No
Yes
Is the primary circulation pump
soiled? Clean the circulation pump (inside).
Check the primary circulation pump for
soiling.
Is the expansion
tank correctly connected to
the supply conduit?
Yes
Check whether the pressure sensor is soiled.
See page 116.
Is the pressure sensor
soiled?
page 83
44
Replace the pressure sensor.
See page 116.
Clean the pressure sensor.
Yes
No
Connect the expansion tank to the return
conduit.
Yes
No
No
8
page 31
Has the malfunction been
repaired?
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!52
Operating code 2P
Check the supply and safety sensors
(page 89).
Are the supply and safety
sensors okay?
Check the primary
circulation pump.
Is the primary circulation
pump okay?
Yes
Yes
Yes
Yes
Yes
Open the servicing cocks.
Replace the supply and/or safety sensors
(page 91).
Replace the primary
circulation pump.
No
No
No
No
No
Is the pressure
in the heating system (measured on
the boiler) at least
14.5 psi (1 bar)?
Yes
Fill and bleed the heating system.
No
Open a thermostatic valve.
Is at least
one thermostatic valve open?
page 83
44
8
page 31
Wait approx. 30 seconds until the boiler
automatically becomes operational again.
fault message ?
P2
Temperature increase of supply sensor or safety
sensor is more than 7.5 °F/sec (5 K/sec). Operating code
2P
21 2
Are all servicing cocks
open?
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 53
Operating code 2U
Wait approx. 30 seconds until the boiler
automatically becomes operational again.
fault message ?
U2
Check the supply and return sensors
(page 89).
The temperature difference between the supply
and return sensors is more than 90 °F (50 K). Operating code
2U
21 3
Are the supply and return
sensors okay?
Check the primary
circulation pump.
Is the primary circulation
pump okay?
Yes
Yes
Yes
Yes
Yes
Open the servicing cocks.
Replace the supply and return sensors
(page 91).
Open a thermostatic valve.
Replace the primary
circulation pump.
No
No
No
No
No
Is at least
one thermostatic valve open?
page 83
44
8
page 31
Are all servicing cocks
open?
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!54
Blocking boiler-fault code 3A
Check that both the plug-and-socket
connections of the blower are correctly fitted.
See page 88, fig 12.
The air fan has failed during the operating
phase. Locking boiler-fault code.
3A
264
Check blower – activation 120V AC
See page 86.
Are the plug-and-socket
connections fitted correctly?
Tacho wire okay?
Has the malfunction been repaired?
Yes
Yes
Yes
Yes
Reconnect the plug-and-socket connection of
the blower. See page 88, fig 12.
No
No
No
No
Is the activation okay?
page 83
44
23
page 55
Check the tacho wire of the blower.
See page 88.
Replace the tacho wire (page 88).
Check that the mains voltage is
120V AC.
Yes
No
Sufficient mains voltage? Have the electrical system tested.
Check whether you can remedy the fault by
temporarily fitting a new blower.
See page 88, paragraph 8.1.6.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 55
Blocking boiler fault code 3A-2Blocking boiler fault code 3F
The blower is switched off during the safety
test. Locking boiler-fault code.
3F
273
Yes
44
page 83
No
23
page 54
Is the supply cord okay?
Check the supply cord of the blower
(120V AC). See page 87.
Replace the supply cord.
page 83
44
Fully switch off the heat request and check
that the blower is still operational after
1 minute.
Is the blower
still operational?
Yes
No
8
page 31
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!56
Locking boiler fault code 3L
Check that both the plug-and-socket
connections of the blower are correctly fitted.
See page 88, fig 12.
Check blower – activation 120V AC.
See page 86.
Are the
plug-and-socket connections fitted
correctly?
Tacho wire okay?
Attempt to rectify the fault by temporarily
replacing the blower.
See page 88.
Has the malfunction been repaired?
Yes
Yes
Yes
Yes
Reconnect the plug-and-socket connection of
the blower. See page 88, fig 12.
No
No
No
No
Is the activation okay?
page 83
44
24
page 57
Check the tacho wire of the blower.
See page 88.
Replace the tacho wire. See page 88.
The blower is switched off during the safety
test. Locking boiler-fault code.
L3
142
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 57
Locking boiler fault code 3L-2
Locking b oiler-fault code 3P (flashing)
Yes
44
page 83
No
24
page 56
Is the supply cord okay?
Check the supply cord of the blower
(120V AC). See page 87.
Replace the supply cord.
8
page 31
Check to see if the blower
is soiled or wet.
Check that the mains voltage is
120V AC.
Is the blower dry and
clean?
Has the malfunction been repaired?
Yes
Yes
Yes
Clean or replace the blower.
See page 88.
No
No
No
Sufficient mains voltage?
page 83
44
Try to remedy the fault by integrating another
provisional blower. See page 88.
Have the electrical system tested.
The blower is running too slowly. Locking boiler-fault code.
P3
162
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!58
Locking boiler-fault code 3Y (flashing)
Check the tacho wire by measuring the
resistance (is the wire broken?).
See page 88.
The blower is running too fast. Locking boiler-fault code.
3Y
152
Check the plug-and socket connection of the
tacho wire to the blower. This is the thin plug.
See page 88, fig 12.
Is the plug-and-socket
connection okay?
Has the malfunction been repaired?
Yes
Yes
Yes
Restore the plug-and-socket connection.
No
No
No
Tacho wire okay?
page 83
44
Attempt to rectify the fault by temporarily
fitting another blower. See page 88.
Replace the tacho wire.
Check that the mains voltage is
120V AC.
Yes
No
Sufficient mains voltage? Have the electrical system tested.
Check that there is no blockage in the blower
or the heat exchanger and that the flue-gas
system is connected.
Yes
No
Did you find a
blockage? Deal with blockage.
Check to see if there is a second blower in the
flue gas outlet conduit or air inlet system.
Is a second
blower fitted? Take the second blower out of service.
No
Yes
Check to see if the blower wheel has come
loose at the motor spindle.
Yes
No
Blower wheel loose?
Replace the blower.
See page 88, par. 8.1.6.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 59
Locking boiler fault code 4A
The supply sensor has measured a
temperature higher than 221 °F (105 °C). Locking boiler-fault code.
The return sensor has measured a
temperature higher than 221 °F (105 °C). Locking boiler-fault code.
A4
182
AC
862
New fault message
?
AC
A4
Are all servicing cocks
open?
Check the supply or return sensor (page 89).
Are the supply and
return sensors okay?
Yes
Yes
Yes
Yes
Yes
Open the servicing cocks.
Replace the supply and return sensor
(page 91).
No
No
No
No
No
Is the
system pressure (measured on the
boiler) in the heating system at least
14.5 psi (1 bar)?
Yes
Fill and bleed the heating system.
No
Open a thermostatic valve.
Check the primary
circulation pump.
Is the primary circulation
pump okay?
Replace the primary
circulation pump.
page 83
44
Is at least
one thermostatic valve
open?
Press the "Reset" button.
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!60
Locking boiler-fault code 4C (flashing)Locking boiler-fault code 4E (flashing)
Locking boiler-fault code 4E (flashing)
The UBA 3 does not register the short cut
bestween the unused contacts 22 and 24. Locking boiler-fault code.
C4
242
Check the contact between the UBA 3
and the UBA 3 mounting base.
See page 126, fig 110.
Is the contact okay?
Has the malfunction been repaired?
Yes
Yes
Restore the contact between the UBA 3 and
the UBA 3 mounting base.
See page 125, fig 109.
No
No
page 83
44
Try to remedy the fault by replacing the entire
cable loom.
8
page 31
Measure the voltage to check for a possible
short circuit in the supply or safety sensor
wiring. See page 126.
Is the wiring
okay?
Yes
Replace the cable loom or the affected part
thereof.
No
page 83
44
The sensor test has failed. Locking boiler-fault code.
E4
782
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 61
Locking boiler fault code 4L
The safety sensor is shorted or measures
temperatures higher than 266 °F (130 °C). Locking boiler-fault code.
L4
202
New fault message ?
L4
Yes
No
Yes
No
Is the wire okay?
26
page 62
25
page 62
Are all servicing cocks
open?
Is the pressure in the
heating system at least
14.5 psi (1 bar)?
Is at least
one thermostatic valve
open?
Check the primary
circulation pump.
Is the primary circulation
pump okay?
Yes
Yes
Yes
Yes
Open the servicing cocks.
Fill and bleed the heating system.
Open a thermostatic valve.
Replace the primary
circulation pump.
No
No
No
No
Check the wire to the safety sensor for signs
of short circuiting (page 92).
Replace the cable loom or the affected part
thereof.
Press the "Reset" button.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!62
Locking boiler fault code 4L-2
Locking boiler fault code 4P
Yes
44
page 83
Check the safety sensor (page 89).
Is the safety sensor okay? Replace the safety sensor (page 91).
No
25
page 61
26
page 61
8
page 31
Check the safety sensor (page 89).
Is the safety sensor okay? Replace the safety sensor (page 91).
Yes
No
Yes
No
Is the wire okay?
Check the wire to the safety sensor for the
correct contact (page 92).
New fault message ?
P4
Yes
No
The safety sensor contact is interrupted. Locking boiler-fault code.
P4
212
44
page 83
Replace the cable loom or the affected part
thereof.
Press the "Reset" button.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 63
Locking boiler fault code 4U
Check the supply and return sensor
(page 89).
Are the supply and return
sensors okay?
Replace the supply and return sensor
(page 91).
Yes
No
Yes
No
Is the wire okay?
Check the wire to the supply or return sensor
for signs of short circuiting (page 92).
New fault message
or ?
U
4
UC
Yes
No
44
page 83
Replace the cable loom or the affected part
thereof.
Press the "Reset" button.
8
page 31
The supply sensor contact is shorted. Locking boiler-fault code.
The return sensor contact is shorted. Locking boiler-fault code.
U4
222
UC
402
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!64
Locking boiler fault code 4Y
Check the supply and return sensor
(page 89).
Are the supply
and return sensors okay? Replace the supply and return sensor
(page 91).
Yes
No
Yes
No
Is the wire okay?
Check the wire to the supply or return sensor
for the proper contact (page 92).
New fault message
or ?
4Y
CY
Yes
No
The supply sensor contact is interrupted. Locking boiler-fault code.
The return sensor contact is interrupted. Locking boiler-fault code.
4Y
232
CY
412
44
page 83
Replace the cable loom or the affected part
thereof.
Press the "Reset" button.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 65
Locking boiler fault code 6A
Is the
heating system propane
gas-fired?
No ionization after four startup attempts. Locking boiler-fault code.
A6
272
Yes
No
31
page 71
30
page 66
Is the
hot surface ignitor activated
during the operating
code .
C0
Yes
Yes
Bleed the gas supply pipe. See page 106.
No
Measure the static inlet gas pressure.
See page 107.
Contact the gas utility company to ensure that
no nitrogen remains in the gas tank or gas
supply pipes.
Is the
inlet gas pressure
okay?
No 28 page 68
27 page 71
Bleed the gas supply pipe. See page 106.
Has the gas supply pipe
been bled of air?
29 page 68
Check the hot surface ignitor is activated
during the operating code .
See page 92.
C0
Replace the hot surface ignitor.
See page 94.
Is the resistance of the
hot surface ignitor
okay?
Check the resistance of the hot surface
ignitor. See page 93.
Yes
Yes
No
No
New fault message ?
A6
No
Yes
Press the "Reset" button.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!66
Locking boiler fault code 6A -2
Check the hot surface ignitor glows
during the operating code .
See page 92.
C0
31
page 71
34
page 67
Yes
Yes
Adjust the gas/air ratio.
See page 108.
No
Is the gas valve
open?
No 32 page 69
Measure the dynamic inlet gas pressure.
See page 107.
Is the
dynamic inlet gas pressure
okay? 33 page 70
No
30
page 65
Check the gas valve is opened during the
operating code .
See page 98.
L0
Is the gas/air ratio correctly
adjusted?
Measure the gas/air ratio during the startup
phase. See page 108.
Yes
Fit the correct gas orifice.
See page 127, table 5.
No
Was the
correct gas orifice
fitted?
Check that the correct gas orifice was fitted.
See page 127, table 5.
Yes
Replace the hot surface ignitor.
See page 94.
Does the
hot surface ignitor activated
glow during the operating
code ?
C0
Yes
No
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 67
Locking boiler fault code 6A -3
31
page 71
No
Measure the ionization current.
See page 95.
Is the ionization current
okay? 35 page 71
34
page 66
Check the following elements for soiling,
damage and correct assembly:
- the combustion-air inlet conduit
- the air suction tube
- the seal between the Venturi and the blower
- the gas orifice, see page 101 and
page 127, table 5
- the blower, see page 86
- the connection between the blower and the
burner
- the burner
- the heat exchanger, see page 117
- the flue gas conduit.
Are the above-
mentioned components clean and
free from damage?
Yes
No
Yes
Clean and/or replace the corresponding
components.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!68
vorh6A Branch 036A Branch 04
Check whether the gas stop tap is open.
See page 101.
31
page 71
Yes
No
Did you
find a blockage? Deal with blockage.
Check to see if there is a blockage in the
conduit between the gas stop tap and gas
valve.
Is the gas stop tap open?
Yes
No
28
page 65
Open the gas stop tap. See page 101.
Deal with blockage.
Check for blockages in the remaining section
of the gas supply pipe.
If the required inlet gas pressure is not
available, you should consult your gas utility
company.
Yes
No
Did you
find a blockage?
31
page 71
Yes
Is the wiring okay?
Measure the resistance in the wires between
the switch of the hot surface ignitor and the
UBA 3. See page 99.
No
29
page 65
44
page 83
Replace the cable loom or the affected part
thereof.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 69
6A Branch 05 v1 v8
31
page 71
Yes
Is the plug-and-socket
connection okay?
Reconnect the plug-and-socket connection at
the gas valve. See page 99.
Check the plug-and-socket connection of the
gas valve. See page 99.
No
32
page 66
44
page 83
Does the gas valve receive power? Replace the gas valve.
See page 101.
Check the gas valve during the
operating code to make sure it receives
power then. See page 98.
L0
No
Yes
Measure the resistance in the wires between
the gas valve plug and
the UBA 3 mounting base.
Yes
No Replace the cable loom or the affected part
thereof.
Is the wiring okay?
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!70
6A Branch 06
Check whether the gas stop tap is open.
See page 101.
31
page 71
Yes
No
Did you find a blockage? Deal with blockage.
Check for blockages in the remaining section
of the gas supply pipe.
Is the gas stop tap open?
Yes
No
33
page 66
Open the gas stop tap. See page 101.
Deal with blockage.
Check for blockages in the remaining section
of the gas supply pipe.
Check whether the overall gas-conduit
network is of sufficient capacity.
Yes
No
Is the overall gas-conduit
network of sufficient capacity?
Consult the utility
company.
Reinforce the gas-conduit network.
No
Yes
Did you find a blockage?
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 71
6A Branch 07
6A Branch 08
31
page 71
35
page 67
Correctly insert the plug into its socket.
No
Yes
Measure the resistance in the wires between
the ionization electrode plug and the UBA 3
mounting base. See page 95.
Yes
No
Check the ionization electrode and replace it
if necessary. See page 97
Check the plug-and-socket connection
between the ionization electrode and cable
loom. See page 95.
Replace the cable loom or the affected part
thereof.
Is the plug-and-socket
connection okay?
Is the wiring okay?
No
31
pages 65 to 71
Remedy the fault using the structure diagram
that corresponds with the fault code.
Yes
No
Yes
Has a new fault code
occurred?
No
Has a new locking boiler fault
code occurred?
A6
Did you
go through all structure diagrams
thru 35 ?
Yes
27
page 65
44
page 83
Press the "Reset" button.
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!72
Locking boiler fault code 6C
Locking boiler fault code 6C-2
An ionization current was measured before
the burner start. Locking boiler-fault code.
C6
282
8
page 31
44
page 72
Replace the ionization electrode.
See page 97.
Yes
Check the ionization electrode for soiling.
Damage see page 95.
Is the ionization electrode
okay?
No
New fault message ?
C6
No
Yes
Press the "Reset" button.
Replace the gas valve.
See page 101.
8
page 31
page 77
Is the burner still under
pressure?
Yes
Check that the burner is still under pressure
after the heat request has ended.
See page 108, par. 8.1.26.
No
An ionization current was measured after the
burner switch-off. Locking boiler-fault code.
C6
063
44
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 73
Blocking boiler-fault code 6L
Yes
No
41
page 77
40
page 74
Yes
Yes
Bleed the gas supply pipe. See page 106
No
Measure the static inlet gas pressure.
See page 107.
Is the static inlet gas pres-
sure okay?
No 38 page 75
Has the gas supply pipe
been bled of air?
No
Ionization fails during the operating phase. Locking boiler-fault code.
6L
229
Bleed the gas supply pipe. See page 106.
Is the
dynamic inlet gas pressure
okay? 39 page 76
Measure the dynamic inlet gas pressure.
See page 107.
Measure the gas/air ratio during the startup
phase. See page 108.
Yes
Adjust the gas/air ratio.
See page 108.
Is the gas/air ratio correctly
adjusted?
No
Yes
Ensure that no nitrogen remains in the gas
tank or gas supply pipes, in close consultation
with the gas utility company.
Is the
heating system propane
gas-fired?
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!74
Blocking boiler-fault code 6L - 2
41
page 77
No
Measure the ionization current.
See page 95.
Is the ionization current
okay? 42 page 77
40
page 73
Check the following elements for soiling,
damage and correct assembly:
- the combustion-air inlet conduit
- the air suction tube
- the seal between the Venturi and the blower
- the gas orifice, see page 101 and
page 127, table 5
- the blower, see page 86
- the connection between the blower and the
burner
- the burner
- the heat exchanger, see page 117
- the flue gas conduit
Are the above-
mentioned components clean and
free from damage?
Yes
Yes
Was the
correct gas orifice
fitted?
Fit the correct gas orifice.
See page 127, table 5.
Check that the correct gas orifice was fitted.
See page 127, table 5.
No
No
Yes
Clean and/or replace the corresponding
components.
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 75
Blocking boiler-fault code 6L - br12
41
page 77
Yes
Yes
Deal with blockage.
No
Is the gas stop tap
open?
No
Did you find a blockage?
No
38
page 73
Did you find a blockage? Yes
Open the gas stop tap. See page 101.
Deal with blockage.
Check whether the gas stop tap is open.
See page 101.
Check to see if there is a blockage in the gas
conduit section between the gas stop tap and
gas valve.
Check for blockages in the remaining section
of the gas supply pipe.
If the required inlet gas pressure is not
available, you should consult the relevant
gas utility company.
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!76
Blocking boiler-fault code 6L branch 13
41
page 77
Yes
No
Deal with blockage.
Check to see if there is a blockage in the gas
conduit section between the gas stop tap and
gas valve.
Yes
No
39
page 73
Open the gas stop tap. See page 101.
Deal with blockage.
Check for blockages in the remaining section
of the gas supply pipe.
Check whether the overall gas-conduit
network is of sufficient capacity.
Yes
No
Is the overall gas-conduit
network of sufficient capacity?
Consult the gas utility company.
Reinforce the gas-conduit network.
No
Yes
Check whether the gas stop tap is fully open.
See page 101.
Is the gas stop tap
fully open?
Did you find a blockage?
Did you find a blockage?
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 77
Blocking boiler-fault code 6L branch 14
locking boiler fault code 6L Zijtak 1e 5
41
page 77
42
page 74
No
Yes
Is the wiring okay?
Measure the resistance in the wires between
the ionization electrode plug and the UBA 3
mounting base. See page 99.
Yes
No
Replace the ionization electrode.
See page 97
Check the plug-and-socket
connection between the ionization electrode
and cable loom. See page 95.
Replace the cable loom or the affected part
thereof.
Is the plug-and-socket
connection okay?
Correctly insert the plug into its socket.
44
page 83
No
41
page 73 – page 77
Remedy the fault using the structure diagram
that corresponds with the fault code.
Yes
No
Yes
Has a new fault code
occurred?
No
Has a new locking boiler fault
code occurred?
L6
Did you
go through all structure diagrams
thru 14?
Yes
44
page 29
Press the "Reset" button.
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!78
Locking boiler-fault code 6P (flashing)
Locking boiler-fault code 7C Locking boiler-fault code 7L (flashing)
Has the malfunction been repaired?
Yes
No KIM defective, contact the Buderus customer
service department. See on the back side of
this document.
Press the "Reset" button.
The hot surface ignitor activates too long. Locking boiler-fault code.
P6
692
8
page 31
Yes
No
The power supply was interrupted
after a fault message. Locking boiler-fault code.
C7
312
Remedy the fault using the structure diagram
that corresponds with the fault code.
Has a new fault code
occurred?
Press the "Reset" button.
8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 79
Operating code 8Y
Restore the contact.
Is the cable loom okay?
Measure the cable loom between the UBA 3
and the terminal strip.
See page 126, fig 110.
Check the contact between the UBA 3
and the UBA 3 mounting base.
Is the contact okay?
44
page 83
Replace the cable loom or the affected part
thereof.
The external switch contact is activated. Locking boiler-fault code.
8Y
232
No
Check that the switch contact is
connected to the boiler.
See page 106, fig. 54, pos. 5 "EV".
Is the external switch
contact open?
No
No
Yes
Yes
Yes
Yes
No
Check to see if an external switch contact
is open, by measuring its resistance using a
volt-ohm-multimeter
Is an external switch
contact connected? 43
page 80
External switch contact has energized.
8
page 31
The UBA 3 is defective. Locking boiler-fault code.
The UBA 3 is defective. Locking boiler-fault code.
L7
612
L7
802
44
page 83
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!80
Operating code 8Y dl 2
Locking boiler fault codes 9A, 9H, 9P, 9U, E
No
43
page 79
Yes
Is there a bridge wire?
Check to see if a bridge wire is present.
See page 106, fig. 54, pos. 5 "EV".
Restore the bridge on the terminal strip again
(see page 106, fig. 54).
Restore the contact.
Is the cable loom okay?
Measure the cable loom between the UBA 3
and the terminal strip.
See page 126, fig 110.
Check the contact between the UBA 3 and
the UBA 3 mounting base.
Is the contact okay?
No
No
Yes
Yes
44
page 83
Replace the cable loom or the affected part
thereof.
8
page 31
New
fault message or
or or or ?
A9
H9
P9
U9
E
Yes
No
44
page 83
Press the "Reset" button.
8
page 31
KIM or UBA 3 is defective. Locking boiler-fault code.
KIM or UBA 3 is defective. Locking boiler-fault code.
KIM or UBA 3 is defective. Locking boiler-fault code.
KIM or UBA 3 is defective. Locking boiler-fault code.
+ any digit or letter to KIM or UBA 3 is defective. Locking boiler-fault code.
+ any digit or letter The UBA 3 is defective. Locking boiler-fault code.
A9
352
H9
372
P9
392
U9
332
E
422
872
E
290
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 81
Locking boiler fault code 9L
Yes
No
Yes
No
Yes
No
The gas valve coil or the wiring to the gas
valve is defective. Locking boiler-fault code.
The UBA 3 is defective. Locking boiler-fault code.
L9
342
L9
382
Check the plug-and-socket connection of the
gas valve. See page 98, par. 8.1.18.
Is the resistance correct? Replace the gas valve.
See page 101.
Is the wire okay? Replace the cable loom or the affected part
thereof.
Restore the plug-and-socket connection.
See page 98, par. 8.1.18.
Measure the wire between the gas valve
and the UBA 3.
See page 99, fig 8.1.20.
Measure the resistance of the two gas valve
coils. See page 101, par. 8.1.22.
44
page 83
New fault message ?
L9
No
Yes
Press the "Reset" button.
Is the plug-and-socket
connection okay?
8
page 31
Diagnosis7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!82
Locking boiler fault code H 7/P--
Check the wiring between the pressure
sensor and the UBA 3 mounting base by
measuring the resistance (fracture).
See page 126, fig 110.
The UBA 3 has no connection to the pressure
sensor or there is a short circuit. Locking boiler-fault code.
Short circuit in connection to pressure sensor. Locking boiler-fault code.
0C
882
0C
892
Check the plug-and socket connection of the
pressure sensor. See page 8, fig. 1, pos. 17.
Is the plug-and-socket
connection okay?
Has the malfunction been repaired?
Yes
Yes
Yes
Restore the plug-and-socket connection.
No
No
No
Is the wiring okay?
page 83
Try to remedy the fault by integrating
another provisional pressure sensor.
See page 116.
Replace the cable loom or the affected part
thereof.
44 8
page 31
Diagnosis 7
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 83
Replace the UBA
No
No
Press the "Reset" button and hold it for
2 seconds. See page 9.
44
Check the contacts between the UBA 3 and
the UBA 3 mounting base, between the BC10
and the base plate and all other plug-and-
socket connections.
See from page 92.
Is the same fault message
displayed?
Has a new fault occurred?
Has the UBA 3 already
been replaced?
Call the Buderus customer service department.
See on the back side of this document.
Remedy the fault using the structure diagram
from this document that corresponds with the
fault code.
Replace the UBA 3. See page 125.
Remedy contact faults.
See from page 92.
Yes
Yes
No
Yes
8
page 31
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!84
8Actions
8.1 Testing, measuring, adjusting and replacing
various components
8.1.1 Checking the UBA 3 fuse; replace if necessary
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Loosen the fastening screw of the UBA 3 by turning it counter-
clockwise (see fig. 4, pos. 1).
-Remove the UBA 3 once the fastening screw is fully loosened
by pulling it forward carefully as indicated by the arrow (see
fig. 4, pos. 2).
-Dismantle the fuse holder by loosening the bayonet connector
(see fig. 5, pos. 1).
-Remove the fuse from the fuse holder.
-Check the circuit continuity through the fuse using the volt-ohm-
multimeter. If broken, replace it by (a new) spare ceramic fuse
5 amps, 250V fast blow (F5AH, 250V) (fig. 5, pos. 2).
-Re-assemble the UBA 3 in reverse order of disassembly.
-Fasten the UBA 3 by only turning the fastening screw clock-
wise.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 4 Dismantling the UBA 3
1
2
WARNING!
Do not pull or move side to side the UBA 3
during loosening or tightening of UBA 3 fastening
screw.
fig. 5 Checking the fuses
2
1
WARNING!
Do not push or force the UBA 3 in place by hand.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 85
8.1.2 External connection board fuse
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove the cover from the connection box (fig. 6).
-Dismantle the fuse holder (fig. 7, pos. 10).
-Remove the fuse from the fuse holder.
-Check the circuit continuity through the fuse using the volt-ohm-
multimeter. If broken, replace it with a (new) ceramic fuse
5 amps, 250V fast blow (F5AH, 250V).
-Re-install the cover on the connection box.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 6 Removing the cover from the connection box
fig. 7 External connection board
pos. 1: RC Room thermostat (connection color orange)
pos. 2: Outdoor-temperature sensor (connection color
blue)
pos. 3: Potential-free On/Off thermostat (connection color
green)
pos. 4: DHW temperature sensor (connection color grey)
pos. 5: External switching contact, potential-free for floor
heating safety etc. (connection color red)
pos. 6: DO NOT USE
pos. 7: Primary loop pump 120V 60Hz (connection color
green)
pos. 8: DHW tank pump 120V 60Hz (connection color grey)
pos. 9: DHW recirculating pump 120V 60Hz (connection
color lilac)
pos. 10: main connection 120V 60Hz (connection color
white)
pos. 11: Fuse holder
RC FA WA FW EV
PK PS PZ Grid
12345 6 78910
11
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!86
8.1.3 Checking the fan unit; 120 VAC control
-Remove the casing.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Disconnect the 120V AC plug of the fan unit.
-Test the voltage with the volt-ohm-multimeter; set it to VAC.
Minimum value 250V AC.
-Connect the volt-ohm-multimeter to the outer two plug contacts
(blue and brown) (see fig. 8).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Start up the boiler in accordance with the "Flue gas test" menu.
See page 10 "Flue gas test" menu.
-Check that while the operating code [0/l/\| is displayed,
120V AC is available on the outer two contacts (blue and
brown) of the plug (see fig. 8).
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Reconnect the plug to the fan unit.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 8 Checking for 120V AC voltage
NOTE
The fan unit can be controlled using the RC control
device relay test function. Further instructions for
the RC control device are in the Installation and
Maintenance Instructions.
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 87
8.1.4 Checking the fan unit; supply cord (120V AC)
-Remove the casing.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Disconnect the 120V AC plug of the fan unit.
-Loosen the fastening screw of the UBA 3 (see fig. 9, pos. 1).
-Remove the UBA 3 by pulling it forward as indicated by the
arrow (see fig. 9, pos. 2).
-Set the volt-ohm-multimeter to "Resistance testing".
-Test the fan unit supply cord to make sure that there is no short
circuit in it and that it is not broken anywhere (see fig. 10 and
fig. 110 on page 126).
-Reconnect the plug to the fan unit.
-Re-assemble the UBA 3 in reverse order of disassembly.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Fit the casing.
fig. 9 Dismantling the UBA 3
fig. 10 UBA 3 installation base
1
2
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!88
8.1.5 Checking the fan unit; tacho cable
-Remove the casing.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Dismantle the tacho cable plug.
-Loosen the fastening screw of the UBA 3 (see fig. 9, pos. 1).
-Remove the UBA 3 by pulling it forward as indicated by the
arrow (see fig. 9, pos. 2).
-Test the tacho cable to make sure that there is no short circuit
in it and that it is not broken (see fig. 11).
-Assemble the tacho cable plug.
-Re-assemble the UBA 3 in reverse order of disassembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.6 Replacing the fan unit
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove both cable plugs from the fan unit
(see fig. 12, pos. 1).
fig. 11 UBA 3 installation base
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
fig. 12 Disconnect the cable plug from the fan unit
1
NOTE
Follow the installation instructions for 120V fan
units!
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 89
-Remove the air suction tube (see fig. 13, pos. 1).
-Remove the fan unit fastening screw (see fig. 13, pos. 2).
-Remove the fan unit by swinging it to the right
(see fig. 13, pos. 3).
-Install the new fan unit.
-Install the fastening screw, air suction tube and both plugs.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.7 Checking the supply/return/safety/hot-water temper-
ature sensors
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
fig. 13 Dismantling the fan unit
123
fig. 14 Checking the supply/return sensors
V
1
2
NOTICE
The current temperature measured by the supply,
return and safety sensors, can be read out from the
RC control device.
For further instructions, see installation and main-
tenance instructions of the RC control device.
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!90
-Disconnect the plug and socket connection of the cable for the
sensor concerned.
-Test the resistance of the sensor concerned.
Supply sensor see fig. 14, pos. 1.
Return sensor see fig. 14, pos. 2.
Safety sensor see fig. 15, pos. 1.
-Measure the temperature near the sensor using a seconds
thermometer.
-Compare the values measured to the values in table 4 on the
next page. If the values differ, the sensor is broken.
-Reconnect the plug and socket connection if the sensor is OK.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 15 Checking the safety sensor
1
Temperature in Resistance in
°F °C Ω
32 0 29,490
41 5 23,462
50 10 18,787
59 15 15,136
68 20 12,268
77 25 10,000
86 30 8,197
95 35 6,754
104 40 5,594
113 45 4,656
122 50 3,893
131 55 3,271
140 60 2,760
149 65 2,339
158 70 1,990
167 75 1,700
176 80 1,458
185 85 1,255
194 90 1,084
203 95 940
212 100 817
table 4 Sensor resistance values (target values)
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 91
8.1.8 Replacing the supply/return/safety sensors
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the maintenance shut-off valves.
-Drain the Logamax plus GB142.
-Disconnect the plug and socket connection.
-Unscrew the sensor concerned and replace it by a new one.
Supply sensor see fig. 16, pos. 1.
Return sensor see fig. 16, pos. 2.
Safety sensor see fig. 17, pos. 1.
-Restore the plug and socket connection.
-Open the maintenance shut-off valves.
-Purge air from the boiler.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.9 Checking the hot-water temperature sensor
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the cable for the
hot-water temperature sensor.
-Pull out the sensor and replace it by a new one.
-Restore the plug and socket connection.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 16 Replacing the supply/return sensors
1
2
fig. 17 Replacing the safety sensor
1
NOTICE
Fill and purge the Logamax plus GB142 as
required. See installation and maintenance instruc-
tions Logamax plus GB142-24/30/45/60.
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!92
8.1.10 Checking the supply/return/safety sensors cable
-Check all plug and socket connections of the sensors and the
UBA 3. A plug that has not been inserted correctly may be the
cause for a fault message. Then start the boiler by pressing
"Reset" c.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Loosen the fastening screw of the UBA 3 (see fig. 18, pos. 1).
-Remove the UBA 3 by pulling it forward as indicated by the
arrow (see fig. 18, pos. 2).
-Disconnect the plug and socket connection of the cable for the
sensor.
-Check the cable between the plug and socket connection and
the 81-pole plug in the UBA 3 installation base (see fig. 19)
using a circuit continuity testing device.
See the electric circuit diagram, fig. 110 on page 126.
-Test this in a straight line twice and test it diagonally twice.
-Restore the plug and socket connection if the cables are OK.
-Install the UBA 3.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.11 Checking the hot surface ignitor; control
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the hot surface
ignitor.
-Set the measuring device to 120V AC.
-Connect the measuring device to the plug on the cable
harness.
-Connect the heating system to the power supply, insert the
main fuse or switch on the circuit breaker.
fig. 18 Dismantling the UBA 3
1
2
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
fig. 19 UBA 3 installation base
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
NOTICE
The hot surface ignitor can be controlled using the
RC control device relay test function. Further
instructions for the RC control device are in the
installation and maintenance instructions.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 93
-Set the main switch on the BC10 to "1" (On).
-Start up the boiler in accordance with the "Flue gas test" menu.
See page 10 "Flue gas test" menu.
-Test that during the ignition phase, while the operating code
[0/l/\| is being displayed, 120V AC is measured.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the measuring device.
-Assemble the plug and socket connection of the hot surface
ignitor.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.12 Checking the hot surface ignitor; resistance
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the cable of the
hot surface ignitor.
-Test the resistance of the hot surface ignitor on the plug.
A resistance value between 50 – 300 Ω means that the hot
surface ignitor is OK (see fig. 20).
-Remove the measuring device.
-Reconnect the cable plug if the hot surface ignitor is OK.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.13 Checking the hot surface ignitor; supply cord
-Remove the casing.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Pull the plug of the hot surface ignitor.
-Loosen the fastening screw of the UBA 3 (see fig. 21, pos. 1).
-Remove the UBA 3 by pulling it forward as indicated by the
arrow (see fig. 21, pos. 2).
-Set the volt-ohm-multimeter to "Resistance testing".
fig. 20 Checking the hot surface ignitor
fig. 21 Dismantling the UBA 3
1
2
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!94
-Test the supply cord of the hot surface ignitor to make sure that
there is no short circuit in it and that it is not broken (fig. 23,
fig. 22 and fig. 110 on page 126).
-Fit the plug to the hot surface ignitor.
-Re-assemble the UBA 3 in reverse order of disassembly.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Fit the casing.
8.1.14 Replacing the hot surface ignitor
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the cable of the
hot surface ignitor.
-Loosen the fastening screws (fig. 24, pos. 1).
-Remove the earth cable (fig. 24, pos. 2).
-Remove the mounting plate (fig. 24, pos. 3).
-Remove the hot surface ignitor (fig. 24, pos. 4).
-Install the new hot surface ignitor with a new gasket and attach
the mounting plate with fastening screws (see fig. 24, pos. 1).
-Restore the plug and socket connection of the hot surface
ignitor.
-Fit the casing.
fig. 22 UBA 3 installation base
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
fig. 23 Testing the supply cord of the hot surface ignitor
fig. 24 Replacing the hot surface ignitor
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 95
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.15 Testing the ionization current
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the monitoring
cable.
-Connect the measuring device in series (see fig. 25).
-Set the multi-meter to DC µA.
-Connect the heating system to the power supply, insert the
main fuse or switch on the circuit breaker.
-Set the main switch on the BC10 to "1" (On).
-Start up the boiler in accordance with the "Service Mode" menu.
See page 11 "Service Mode" menu.
-Test the ionization current at partial load. The boiler is in part-
load operation as soon as, in the "Service Mode" menu, [l/3/0|
is selected. The ionization current must be > 1.4 DC µA.
-Remove the measuring device.
-Reconnect the plug and socket connection of the monitoring
cable if the ionization current is OK.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.16 Checking the ionization electrode; cable
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Dismantle the plug and socket connection of the
ionization electrode.
-Loosen the fastening screw of the UBA 3 (see fig. 26, pos. 1).
-Remove the UBA 3 by pulling it forward as indicated by the
arrow (see fig. 26, pos. 2).
fig. 25 Testing the ionization current
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
fig. 26 Dismantling the UBA 3
1
2
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!96
-Test the ionization cable between the plug and socket connec-
tion and the UBA 3 installation base to make sure that it has no
short circuit to earth (see fig. 27 and fig. 110 on page 126) and
that it is not broken anywhere (see fig. 28).
-Assemble the plug and socket connection of the ionization elec-
trode.
-Re-assemble the UBA 3 in reverse order of disassembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 27 Testing the earth connection circuit of the ionization
electrode (1)
fig. 28 Testing the earth connection circuit of the ionization
electrode (2)
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
UBA3
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 97
8.1.17 Checking the ionization electrode; replace if
necessary
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Disconnect the plug and socket connection of the cable.
-Set the volt-ohm-multimeter to "Resistance testing".
-Test the earth connection circuit of the ionization electrode (see
fig. 27). The height of the resistance value must be infinite.
-Loosen the fastening screws (see fig. 29, pos. 1).
-Remove the earth cable (see fig. 29, pos. 2).
-Remove the mounting plate (see fig. 29, pos. 3).
-Dismantle the ionization electrode (see fig. 29, pos. 4).
-Set the volt-ohm-multimeter to "Resistance measurement".
-Test the resistance of the ionization electrode (see fig. 30).
The resistance must be 0 Ω.
-Check the ionization electrode for contamination, wear or
damage (see fig. 31).
-Replace the ionization electrode if required.
-Install a new ionization electrode with a new gasket and secure
the mounting plate with the fastening screws.
-Fit the earth cable (see fig. 29, pos. 2).
-Restore the plug and socket connection.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 29 Replacing the ionization electrode
fig. 30 Testing the resistance of the ionization electrode
fig. 31 Checking the ionization electrode
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!98
8.1.18 Checking the gas control valve; cable connections
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Check that the plug of the gas control valve has been installed
correctly (see fig. 32, pos. 1).
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.19 Checking the gas control valve; Control
-Remove the casing.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Start up the boiler in accordance with the “Flue gas test” menu.
See page 10 "Flue gas test" menu.
-Use a volt-ohm-multimeter to check that, while operating code
[0/l/\| is displayed, there is a voltage on the plug of the gas
control valve. The test must indicate a voltage of 20 – 24 VDC
both when testing on the central and left contacts and when
testing on the central and right contacts (see fig. 33).
-Fit the casing.
fig. 32 Checking the cable connections to the gas control
valve (e.g. HONEYWELL gas control valve)
1
fig. 33 Voltage testing on the gas control valve
NOTICE
You can drive the burner (the gas valve) using the
relay test in combination with the RC control
device. See installation and maintenance instruc-
tions of the RC control device.
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 99
8.1.20 Checking the gas control valve; cable connection
between gas control valve and UBA 3 installation
base
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove the plug of the gas control valve (see fig. 34).
-Loosen the fastening screw of the UBA 3 (see fig. 35, pos. 1).
-Pull the UBA 3 forward in the direction indicated by the arrow
(see fig. 35, pos. 2).
-Test the resistance of the cable between the plug of the gas
control valve and the UBA 3 installation base (see fig. 36,
fig. 37 and circuit diagram, fig. 110 on page 126).
-Reconnect the plug to the gas control valve (see fig. 34).
-Re-install the UBA 3 (see fig. 35).
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 34 Removing the gas control valve plug
WARNING!
Avoid damage: do not push the measuring pin of
the volt-ohm-multimeter too deeply into the socket.
fig. 35 Dismantling the UBA 3
1
2
fig. 36 Testing the cable between the gas control valve and
the UBA 3 installation base
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!100
8.1.21 Ohming out the gas control valve
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove the plug of the gas control valve (see fig. 38).
-Set the volt-ohm-multimeter to "Resistance testing".
Use a scale of 200 Ω or greater.
-Test the resistance of both coils of the gas control valve using
the volt-ohm-multimeter. The resistance measured between
the left and central contacts (see fig. 39) must be approx. 75 Ω
and between the right and central contacts (see fig. 40) this
must be approx. 185 Ω (+/- 10 Ω). If this is not the case, the gas
control valve will probably be defective. It must then be
replaced.
-Attach the plug to the gas control valve.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 37 UBA 3 installation base
Pin 1
28
55
Pin 81
Pin 16
Pin 1
KIM
16-pole connector
81-pole connector
fig. 38 Removing the gas control valve plug
fig. 39 Testing the resistance on the gas burner ass’y (1)
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 101
8.1.22 Replacing the gas control valve
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the gas shut-off valve (see fig. 41, pos. 1).
-Remove the cable plug from the gas control valve (see fig. 42,
pos. 1).
fig. 40 Testing the resistance on the gas burner ass’y (2)
fig. 41 Gas shut-off valve closed (1), gas shut-off valve
open (2)
DANGER
Work on gas pipes and fittings must only be carried
out by a registered service provider.
fig. 42 Removing the gas control valve plug
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!102
-Remove both cable plugs from the fan unit (see fig. 43, pos. 1).
-Loosen the union nut of the gas control valve (see fig. 44,
pos. 1).
-Loosen both sets of retaining clips (fig. 44, pos. 2 and fig. 45,
pos. 1) of the burner cover and remove the burner cover with
the fan unit and the gas burner fitting.
fig. 43 Disconnect the cable plug from the fan unit
1
fig. 44 Loosening the union nut
12
fig. 45 Loosening the retaining clips
1 1
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 103
-Loosen three screws on the gas control valve (see fig. 46,
pos. 1).
-Remove the gas control valve (see fig. 47).
-Remove the gas orifice from the gas control valve (see fig. 48,
pos. 1).
-Install the gas orifice in the new gas control valve.
-Mount the new gas control valve on the fan unit.
-Assemble the burner cover with the fan unit and the gas control
valve.
-Close both retaining clips.
-Tighten the union nut of the gas pipe on the gas control valve.
Make sure that you have inserted the gasket!
-Connect both cable plugs to the fan unit.
-Connect the cable plug to the gas control valve.
-Open the gas shut-off valve (see fig. 49, pos. 2).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 46 Loosening the screws
1
1
1
fig. 47 Dismantling the gas control valve
fig. 48 Dismantling the gas orifice
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!104
You must also check all gaskets and seals affected by the replace-
ment activities during the tightness test carried out in operating
conditions!
-Fit the casing.
8.1.23 Checking the control unit; connections to the boiler
If an On/Off thermostat is used and the boiler does not react to
a heat request:
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove the cover from the connection box (see fig. 50).
-Use a jumper wire to create a bridging circuit between the two
"WA" contacts (see fig. 53, pos. 3).
-Connect the heating system to the power supply, insert the
main fuse or switch on the circuit breaker.
-Set the main switch on the BC10 to "1" (On).
-If the boiler switches to heating mode (operating code [-/h/\| )
after some time, the cause of the fault must be outside the
boiler.
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off). See page 9 „Menu
structure of the BC10 basic controller“.
-Remove the bridge between the two "WA" contacts (see fig. 53,
pos. 3).
-Connect the On/Off thermostat directly to the two "WA"
contacts of the boiler using a short cable (see fig. 53, pos. 3).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Set the On/Off thermostat to the request position.
-If the boiler switches to heating operation (operating code
[-/h/\| ) after some time, the fault is caused by the cable
between the On/Off thermostat and the boiler.
fig. 49 Gas shut-off valve closed (1), gas shut-off valve
open (2)
NOTICE!
Carry out all start-up activities according to the
Installation and Servicing Instructions and
complete the start-up report.
fig. 50 Removing the cover from the connection box
fig. 51 Installing the cover of the connection box
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 105
-If the boiler does not switch to heating mode after some time,
the fault is caused by the On/Off thermostat.
-Correct the cause of the fault.
-Fit the cover on the connection box (see fig. 51).
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
If a modulating control unit is used and the boiler does not
react to a heat request:
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Remove the cover from the connection box (see fig. 52).
-Connect the modulating control directly to the two "RCxx"
contacts of the boiler using a short cable (see fig. 53, pos. 1).
-Connect the heating system to the power supply, insert the
main fuse or switch on the circuit breaker.
-Set the main switch on the BC10 to "1" (On).
-Set the modulating control to the request position.
-If the boiler switches to heating mode (operating code [-/h/\| )
after some time, the fault is caused by the cable between the
modulating control and the boiler.
-If the boiler does not switch to heating mode after some time,
the fault is caused by the modulating control.
-Correct the cause of the fault.
fig. 52 Removing the cover from the connection box
fig. 53 External connection board
pos. 1: RC Room thermostat (connection color orange)
pos. 2: Outdoor-temperature sensor (connection color
blue)
pos. 3: Potential-free On/Off thermostat (connection color
green)
pos. 4: DHW temperature sensor (connection color grey)
pos. 5: External switching contact, potential-free for floor
heating safety etc. (connection color red)
pos. 6: DO NOT USE
pos. 7: Primary loop pump 120V 60Hz (connection color
green)
pos. 8: DHW tank pump 120V 60Hz (connection color grey)
pos. 9: DHW recirculating pump 120V 60Hz (connection
color lilac)
pos. 10: Main connection 120V 60Hz (connection color
white)
pos. 11: Fuse holder
RC FA WA FW EV
PK PS PZ Grid
12345 6 78910
11
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!106
-Fit the cover on the external connection box (see fig. 54).
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.24 Bleed the gas supply pipe
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the gas shut-off valve (see fig. 56, pos. 1).
-Open the screw plug on the testing nipple for the inlet gas pres-
sure and for purging (fig. 55) by two turns and install a hose.
-Open slowly the gas shut-off valve.
-Run the gas that flows out through a water bath.
-Close the gas shut-off valve when no more air escapes.
-Remove the hose and tighten the screw plug again.
-Carefully open the gas shut-off valve (see fig. 56, pos. 2).
-Check the testing nipple for leaks.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 54 Installing the cover of the connection box
fig. 55 Bleeding the gas supply pipe
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 107
8.1.25 Measuring the inlet gas pressure (flow pressure)
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Open at least one thermostatic radiator valve.
-Close the gas shut-off valve (see fig. 56, pos. 1).
-Open the screw plug on the testing nipple for the inlet gas pres-
sure (see fig. 57, pos. 1) by two turns.
-Set the pressure gauge to zero.
-Connect the measuring hose of the pressure gauge to the
testing nipple (see fig. 57, pos. 2).
-Carefully open the gas shut-off valve (see fig. 56, pos. 2).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Put the heating boiler into operation, see "Flue gas test" menu
on page 10.
-Measure the inlet gas pressure when the "Burner" (On/Off) LED
on the BC10 basic controller lights.
-The inlet gas pressure must be:
–for natural gas – min. 3.5 to 10.5 inch W.C (8.7 to 26.1
mbar), nominal supply pressure 7.0 inch W.C. (17,4 mbar)
–for LPG – min. 8.0 to 13.0 inch W.C. (19.9 to 32.3 mbar),
nominal supply pressure 11.0 inch W.C. (27.4 mbar).
-Set the main switch on the BC10 to "0" (Off).
-Close the gas shut-off valve (see fig. 56, pos.1).
-Remove the hose and tighten the screw plug on the testing
nipple again.
-Open again the gas shut-off valve (see fig. 56, pos. 2).
-Check the testing nipple for leaks.
-Fit the casing.
-Set the main switch on the BC10 to "1" (On).
fig. 56 Gas shut-off valve closed (1), gas shut-off valve
open (2)
fig. 57 Measure the inlet gas pressure
NOTE!
If the required inlet gas pressure is not available,
you should consult your gas utility company. If the
inlet gas pressure is too high, a gas pressure regu-
lator is to be integrated upstream of the gas valve.
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!108
8.1.26 Measure and adjust the gas/air ratio
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the gas shut-off valve (see fig. 56, pos. 1).
-Open at least one thermostatic radiator valve.
-Open the screw plug on the testing nipple for the burner pres-
sure (fig. 58, pos. 1) by two turns.
-Set the pressure gauge to zero.
-Use a hose to connect the + connection of the pressure gauge
to the burner pressure measuring nipple (fig. 58, pos. 2).
-Open the gas shut-off valve (see fig. 56, pos. 2).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Put the heating boiler into operation, see "Service Mode" menu
on page 11.
-Read out the gas/air ratio from the pressure gauge when the
boiler is in part-load operation.
The boiler is running in part-load operation when, in the
"Service mode" menu has been set.
-The differential pressure (pGas - pAir) must be
-0.02 inch W.C. (-5 Pa) (+/-0.02 inch W.C. = +/-5 Pa)
(read-out on pressure gauge: -0.04 – 0 inch W.C. =
-10 Pa – 0 Pa). See fig. 59.
-If the gas/air ratio is incorrect, it can be adjusted on the set
screw (fig. 60, pos. 1).
-Set the main switch on the BC10 to "0" (Off).
-Close the gas shut-off valve (see fig. 56, pos. 1).
-Remove the hose and tighten the screw plug on the testing
nipple again.
-Open the gas shut-off valve (see fig. 56, pos. 2).
-Check the testing nipple for leaks.
-Fit the casing.
-Set the main switch on the BC10 to "1" (On).
fig. 58 Checking the gas/air ratio
fig. 59 Differential pressure gas/air ratio part-load
-0.06 -0.04 -0.02 0.020
(inch W.C.)
incorrect incorrect
correct
turn counterclockwise turn clockwise
03L
fig. 60 Adjusting the gas/air ratio
NOTE!
The set screw is located behind the screw-on
cover. This must be removed first.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 109
8.1.27 Measuring the carbon monoxide content (CO)
-Measure the carbon monoxide content on the flue gas sampling
point (see fig. 61).
-The CO values in an air-free condition must be below 400 ppm
or 0.04 vol. %.
-Values of 400 ppm and up indicate that the burner adjustment
may be wrong, the gas burner fitting or the heat exchanger are
dirty or that there may be burner faults.
-You must establish and resolve the cause. The boiler must be
operational when you do this.
8.1.28 Transformer; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Dismantle the cover of the external connection board
(see fig. 62).
-Pull the 4 plugs from the external connection board
(see fig. 63, pos. 1, 2, 3 and 4).
fig. 61 Flue gas sampling point
fig. 62 Removing the cover from the connection box
fig. 63 Pulling the external connection board plug
2
3
1
4
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!110
-Loosen the 2 external connection board fastening screws (see
fig. 64, pos. 1).
-Remove the external connection board (see fig. 65).
-Remove the transformer shield (see fig. 66).
fig. 64 Loosening the fastening screws
1
fig. 65 Removing the external connection board
fig. 66 Removing the transformer shield
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 111
-Pull both plugs on the rear of the transformer (see fig. 67).
-Check to see if you measure any resistance on the two cable
plugs. If you do then the transformer is not the problem. If you
don't measure any resistance then replace the transformer as
described in the following steps.
-Remove the transformer by pulling it in the direction indicated
by the arrow (see fig. 68).
-Install the new transformer.
-Re-assemble all parts and plugs in reverse order of disas-
sembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.29 Automatic air purging system; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the maintenance shut-off valves and drain the Logamax
plus GB142. (see fig. 69).
fig. 67 Pulling the plugs from the transformer
fig. 68 Removing the transformer
fig. 69 Draining the Logamax plus GB142
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!112
-Remove the plastic cover from the top of the boiler (see fig. 70).
-Remove the float cap (see fig. 71).
-Dismantle the valve case by pulling it upwards through the
opening in the housing (see fig. 72).
-Assemble the new valve case and all other parts in reverse
order of disassembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 70 Removing the plastic cover of the automatic air
purging system
fig. 71 Removing the float cap
fig. 72 Dismantling the valve case for the automatic air
purging system
NOTICE
Fill and purge the Logamax plus GB142 as
required.
See installation and maintenance instructions
Logamax plus GB142-24/30/45/60.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 113
8.1.30 Burner; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the gas shut-off valve (see fig. 73, pos. 1).
-Remove the cable plug from the gas control valve
(see fig. 74, pos. 1).
-Remove both cable plugs from the fan unit (see fig. 75, pos. 1).
fig. 73 Gas shut-off valve closed (1), gas shut-off valve
open (2)
fig. 74 Replacing the gas control valve
(e.g. HONEYWELL gas control valve)
1
fig. 75 Disconnecting the cable plug from the fan unit
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!114
-Loosen the union nut of the gas control valve (see fig. 76,
pos. 1).
-Loosen both sets of retaining clips (fig. 76, pos. 2 and fig. 77,
pos. 1) of the burner cover and remove the burner cover with
the fan unit and the gas burner fitting.
-Remove the burner gasket (see fig. 78, pos. 1).
-Remove the gas/air distributor plate (see fig. 78, pos. 2).
-Remove the orifice plate (only applies to Logamax plus
GB142-24/30 and GB142-60) (see fig. 78, pos. 3). Note that
the orifice plate of the GB142-60 has a different shape.
-Remove the burner (see fig. 78, pos. 4).
fig. 76 Loosening the gas control valve
12
fig. 77 Loosening the retaining clips
1 1
fig. 78 Removing the burner
1
2
3
4
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 115
-Install the new burner (see fig. 79).
-Re-assemble all other parts in reverse order of disassembly.
-Open the gas shut-off valve (see fig. 80, pos. 2).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Also check all joints and gaskets affected by the replacement
activities while carrying out the tightness test in operating
conditions.
-Set the gas/air ratio again. See paragraph 8.1.26.
8.1.31 Sight glass; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Loosen both screws of the sight glass (see fig. 81, pos. 1).
-Remove the sight glass mounting plate.
-Disassemble the sight glass inclusive of both gaskets.
-Assemble the new sight glass and all further parts in reverse
order of disassembly; remember to fit new gaskets.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 79 Installing the burner
WARNING!
Fit the burner so that the scale mark is located on
the left-hand side (see fig. 79).
fig. 80 Gas shut-off valve closed (1), gas shut-off valve
open (2)
fig. 81 Loosening the screws of the sight glass
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!116
8.1.32 Condensate trap; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Pull the condensate trap from the condensate plate
(see fig. 82, pos. 1).
-Pull the internal condens bypass pipe from the condensate trap
(see fig. 82, pos. 2).
-Loosen the condensate trap from the connection (see fig. 82,
pos. 3) and remove it.
-Fill the new condensate trap with water.
-Re-assemble the new condensate trap in reverse order of
disassembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
8.1.33 Pressure sensor; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the maintenance shut-off valves and drain the Logamax
plus GB142.
-Remove the cable plug from the pressure sensor.
-Loosen the pressure sensor by removing the securing clip (see
fig. 84).
-Assemble the new pressure sensor and the plug in reverse
order of disassembly.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 82 Disconnecting the condensate trap connection
12
3
fig. 83 Draining the Logamax plus GB142
fig. 84 Loosening the pressure sensor
NOTICE
Fill and purge the Logamax plus GB142 as
required.
See installation and maintenance instructions
Logamax plus GB142-24/30/45/60.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 117
8.1.34 Heat exchanger; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Close the maintenance shut-off valves and drain the Logamax
plus GB142, see 116, fig. 83.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Close the gas shut-off valve(see fig. 85, pos. 1).
-Remove the cable plug from the gas control valve
(see fig. 86, pos. 1).
-Remove both cable plugs from the fan unit (see fig. 87, pos. 1).
fig. 85 Gas shut-off valve closed (1), gas shut-off valve
open (2)
fig. 86 Replacing the gas control valve
(e.g. HONEYWELL gas control valve)
1
fig. 87 Disconnecting the cable plug from the fan unit
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!118
-Loosen the union nut of the gas control valve (see fig. 88,
pos. 1).
-Pull both retaining clips (see fig. 89, pos. 1) on the burner cover
to open them and remove the burner cover with the fan unit and
the gas control valve.
-Remove the burner gasket (see fig. 90, pos. 1).
-Remove the gas/air distributor plate (see fig. 90, pos. 2).
-Remove the orifice plate (only applies to Logamax plus
GB142-24/30 and GB142-60) (see fig. 90, pos. 3). Note that
the orifice plate of the GB142-60 has a different shape.
-Remove the burner (see fig. 90, pos. 4).
fig. 88 Loosening the gas control valve
1
fig. 89 Loosening the retaining clips
1 1
fig. 90 Removing the burner
1
2
3
4
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 119
-Disconnect the plug and socket connections of the supply,
return and safety sensors (see fig. 91, 92 and 93).
fig. 91 Loosening the plug and socket connections of the
supply sensor
fig. 92 Disconnect the plug and socket connection of the
return sensor
fig. 93 Disconnect the plug and socket connection of the
safety sensor
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!120
-Disassemble the supply and return sensors (see fig. 94, pos. 1
and 2).
-Dismantle the safety sensor (see fig. 95, pos. 1).
-Disconnect the hot surface ignitor and ionization electrode
plugs.
-Loosen the fastening screws (see fig. 96, pos. 1).
-Pull the earth cable from the hot surface ignitor (see fig. 96,
pos. 2).
-Dismantle the mounting plate (see fig. 96, pos. 3).
fig. 94 Replacing the supply/return sensors
1
2
WARNING
To prevent mix-ups, the supply sensor is marked
by a red sleeve on the side of the cable harness.
fig. 95 Dismantling the safety sensor
1
fig. 96 Replacing the hot surface ignitor
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 121
-Remove both the hot surface ignitor and the ionization elec-
trode by pulling them loose (see fig. 97, pos. 1).
-Dismantle the condensate trap connection to the condensate
collector (see fig. 98, pos. 1).
-Open the four latches of the condensate collector
(see fig. 99, pos. 1).
fig. 97 Removing the hot surface ignitor and the ionization
electrode
1
fig. 98 Dismantling the condensate trap connection to the
condensate collector
1
2
fig. 99 Opening the latches of the condensate collector
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!122
-Remove the condensate collector (see fig. 100, pos. 1).
-Loosening the backflow connection between the primary pump
and heat exchanger (see fig. 101, pos. 1).
-Dismantle the tension spring between the supply pipe and the
heat exchanger (see fig. 101, pos. 2).
-Loosening with one turn the nut between the supply connection
and three way valve connection AB
(see fig. 102, pos. 2).
-Pull the supply pipe out of the heat exchanger (see fig. 102,
pos. 1).
fig. 100 Removing the condensate collector
1
fig. 101 Loosening the backflow connection and dismantling
the tension spring
1
2
fig. 102 Removing the supply pipe
2
1
WARNING!
Water will be released.
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 123
-Loosen the fastening screws of the combustion air supply and
flue gas exhaust connections (see fig. 103, pos. 1).
-Pull the combustion air supply (see fig. 104, pos. 2) and flue
gas exhaust (see fig. 104, pos. 1) connections on top of the
boiler upwards to remove them.
-Loosen the 6 fastening screws of the flue gas adapter
(see fig. 105, pos. 1).
fig. 103 Loosening the fastening screws of the combustion air
supply and flue gas exhaust connections
1
fig. 104 Loosening the combustion air supply and flue gas
exhaust connections
1
2
fig. 105 Loosening the fastening screws
1
Actions8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!124
-Remove the flue gas adapter (see fig. 105, pos. 1) from the top
of the boiler.
-Remove the heat exchanger by grabbing its bottom end and
pulling forward and then pushing it upwards (see fig. 107,
pos. 1).
-Assemble the new heat exchanger and all other parts in reverse
order of disassembly.
-Open the gas shut-off valve (see fig. 108, pos. 2).
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
-Also check all joints and gaskets affected by the replacement
activities while carrying out the tightness test in operating
conditions.
-Set the gas/air ratio again. See paragraph 8.1.26, page 108.
fig. 106 Removing the flue gas adapter
1
fig. 107 Dismantling the heat exchanger
1
NOTICE!
Fill and purge the Logamax plus GB142 as
required. See installation and maintenance instruc-
tions Logamax plus GB142-24/30/45/60.
Remove the flue gas collector from the old heat
exchanger, including the oval seal. Put silicon kit
on both sides of the oval seal, the flue gas collector
and the heat exchanger. Reassemble the flue gas
collector with the oval seal to the heat exchanger.
Check if the oval seal is placed correctly by
opening the condensate collector (see page 122,
fig. 100).
fig. 108 Gas shut-off valve closed (1), gas shut-off valve open
(2)
Actions 8
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 125
8.1.35 UBA 3; replacing
-Switch off the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "0" (Off).
-Remove the casing.
-Loosen the fastening screw of the UBA 3 (see fig. 109, pos. 1).
-Pull the UBA 3 forward in the direction indicated by the arrow
(see fig. 109, pos. 2).
-Install the new UBA 3.
-Tighten the fastening screw again.
-Fit the casing.
-Switch on the power supply of the heating system on the circuit
breaker.
-Set the main switch on the BC10 to "1" (On).
fig. 109 Dismantling the UBA 3
1
2
Appendix9
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!126
9 Appendix
fig. 110 Electric circuit diagram
4
3 2 1
1 2 3 1
2 3
P
6 7
541 2 3
1 2 3
L
NPE L
N
5
M
120
VAC
1
45
1 2
4
3
2
1
5
4
3
2
1
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
3
2
1
4
3
2
1
57
1
54
51
46
19
77
26
63
64
75
74
36
37
58
57
33
60
35
8
43
34
16
15
8
1
15
16
13
1
Pin 1
28
55 Pin 81
Pin 16 Pin 1
KIM
24 VRAC
78 65 1234
58
2
PZGrid
14 13
NL
PENL
53
79
23
Fan unit Gas burner
fitting Transformer
Hot
surface
ignitor
16-pole connector
(120 VAC)
81-pole connector
(AC 0, 10, 24 and 120 V)
81-pole connector
16-pole connector
Connection box UBA 3.0
Ionization
Earth
Pressure
sensor
Return sensor
Safety-temperature sensor
Supply sensor
Operating switch
Earth
120 VAC
Function module
Mains supply
120 VAC 60 Hz
Circulating pump
120 VAC, max. 250 VA
DHW circulator
120 VAC, max. 250 VA
Boiler circulator
120 VAC, max. 250 VA
External connection for specialist servicing company
External switch contact
Potential-free e.g.
for floor heating
DHW sensor
On/Off temperature
control, potential-free
Outdoor-temperature
sensor
Modulating room controller
BC10 connector
Bus
Function module
External 3-way valve
white greengrey
lilac
120 VAC
Function module
21
DWV
High Voltage
0 VAC
24 VAC
10 VAC
10 VAC
230 VAC
230 VAC
24 VRAC
120 VAC
120 VAC
120 VAC
120 VAC
white red grey blue orangegreen
PS PK
PENLPENL PENL
25 24 63 61
EV FW WA FA RC
21 21321 21 21
65
65
1234
1234
14
13
24
22
39
38
12
11
70
61
62
2
55
1
28
90
81
25
52
27
23
79
53
76
49
16
44
17
45
69
68
67
14
12
13
PE
N
L
L
PE
N
10
11
9
L
N
3
7
4
6
5
WARNING
Label all wires prior to disconnection when servicing.
Wiring errors can cause improper and dangerous operation.
Appendix 9
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 127
-The diameter of the gas orifice islocated on the gas orifice.
-The article number of the Venturi is located on both clamps of
the Venturi (see fig. 111, pos. 1 and 2).
Boiler capacity Type of gas supply Venturi article
number
Gas orifice diameter Altitude 0 - 10,200 ft
No CO2 correction Altitude 4,001 - 10,200 ft
with CO2 correction
[inch] [mm] [inch] [mm]
24 kW Natural gas H423.072A 0.175 4.45 0.179 4.55
LPG P423.072A 0.132 3.35 0.134 3.40
30 kW Natural gas H 423.072A 0.175 4.45 0.177 4.50
LPG P423.072A 0.132 3.35 0.134 3.40
45 kW Natural gas H 423.170A 0.213 5.40 0.219 5.55
LPG P423.170A 0.163 4.15 0.163 4.15
60 kW Natural gas H 423.173A 0.295 7.50 0.301 7.65
LPG P423.173A 0.213 5.40 0.215 5.45
table 5 Gas orifice diameter
Type of gas
supply
Factory setting of gas burner fitting
Natural gas HDelivered factory-set to Wobbe index
14.1 kWh/m3 (based on 59 °F (=15°C),
14.7 psi (=1,013 mbar)), suitable for
Wobbe index range 11.3 – 15.2 kWh/m3.
Information on gas type instruction plate:
Set to gas category: G 20 – 2E.
Previous indications: set to Wobbe index
15.0 kWh/m3 (based on 32 °F (=0°C), 14.7 psi
(=1,013 mbar)), suitable for
Wobbe index range 12.0 – 15.7 kWh/m3.
LPG PSuitable for propane after conversion (also see
the chapter "Conversion to another type of gas
supply").
Information on gas type instruction plate:
Set to gas category: G 31 – 3P.
Table 6 Factory setting of gas burner fitting
fig. 111 Venturi article number
1
2
Spare parts10
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!128
10 Spare parts
Below is a list of the spare parts for this boiler. Look up the position number in the exploded view drawing on the next two pages for the
illustration. Spare parts may be ordered from Buderus.
** not shown in exploded views
Pos. Description Product No.
34 Air inlet pipe; 24/30 kW 7099024
Air inlet pipe; 45/60 kW 7099023
35 Seal Ø50 mm (5 pc) 7099058
36
Venturi 24/30 kW 7099020
Venturi 45 kW 7099925
Venturi 60 kW 7099931
37 Seal set (4 pc) 7099021
38 Fan 78184
39 Gas control valve 7099025
40 Gas supply pipe GB142 USA 76685
41 Spring (5 pc) 7100549
42 Seal 2x16x22 (5 pc) 7098778
43
L.P. Orifice Ø 3.35 - 24/30 kW
0-10,200 ft 76687
L.P. Orifice Ø 3.40 - 24/30 kW
4,001-10,200 ft 7746901353
L.P. Orifice Ø 4.15 - 45 kW
0-10,200 ft 7746901355
N.G. Orifice Ø 4.45 - 24/30 kW
0-10,200 ft 7099016
N.G. Orifice Ø 4.50 - 30 kW
4,001-10,200 ft 7746901421
N.G. Orifice Ø 4.55 - 24 kW
4,001-10,200 ft 7746901354
N.G. Orifice Ø 5.40 - 45 kW
0-10,200 ft 76690
L.P. Orifice Ø 5.40 - 60 kW
0-10,200 ft 76690
L.P. Orifice Ø 5.45 - 60 kW
4,001-10,200 ft 7746901357
N.G. Orifice Ø 5.55 - 45 kW
4,001-10,200 ft 7746901356
N.G. Orifice Ø 7.50 - 60 kW
0-10,200 ft 76686
N.G. Orifice Ø 7.65 - 60 kW
4,001-10,200 ft 7746901358
44 Condensate trap, part of pos. 88 8718600689
45 Seal condensate trap (5 pc) 7100742
47 Supply pipe CH; 24/30/45 kW 75990
Supply pipe CH; 60 kW 75991
48 Return pipe 24/30/45 kW 709965
Return pipe 60 kW 709945
49 Pressure sensor ** 8718600019
50 Bottom plate 7099049
51 Transformer 120V 78191
52 Grommet 7099050
53 External connection board 7099042
54 External connection board cover 7099046
55 Fuse 5 AF slow blow 73904s
56 UBA cover 7099047
57 UBA 3 - 120V 7099707
Pos. Description Product No.
1Casing 24/30 kW 7099988
Casing 45/60 kW 7099901
2 Casing latches left (2 pc) 7099039
3 Casing latches right (2 pc) 7099038
4Casing seal 24/30 kW 7098752
Casing seal 45/60 kW 7098798
5 Wall mounting bracket 7098364
6Back panel 24/30 kW 7099001
Back panel 45/60 kW 7099903
7 Cap air vent 7100250
9 Seal ring Ø 3” 77470s
10 Seal ring Ø 80 mm 7096475
11 Flue gas collector 7098857
12 Oval seal 7098858
13
Heat exchanger 24/30 kW 7746900159
Heat exchanger 45 kW 7746900160
Heat exchanger 60 kW 7746900161
14 Heat exchanger baffle 24/30 kW 7098828
15
Seal condensate collector 24/30 kW 7098834
Seal condensate collector 45 kW 7098838
Seal condensate collector 60 kW 67900522
16
Condensate collector + sealing 24/30 kW 7098840
Condensate collector + sealing 45 kW 7098844
Condensate collector + sealing 60 kW 67900521
17 Clamp 7098848
18 Sensor NTC 7100136
19 Revision set air vent ** 7098822
20 Sight glass 7098575
21
Burner box 24/30 kW 7099057
Burner box 45 kW 7098875
Burner box 60 kW 67900525
22 Safety sensor 78194
23
Seal burner 24/30 kW 7098916
Seal burner 45 kW 7098920
Seal burner 60 kW 67900526
24
Gas/air distribution plate 24/30 kW 7100922
Gas/air distribution plate 45 kW 7098926
Gas/air distribution plate 60 kW 67900527
25 Orifice plate 24/30 kW 7100920
Orifice plate 60 kW 7746900120
26
Burner 24/30 kW 7099003
Burner 45 kW 7098932
Burner 60 kW 67900528
27 Gas-air inlet 7099004
28 Seal fan 7099023
29 Ionization electrode 78195
30 Hot surface ignitor 7099006
31 Shield hot surface ignitor 7100229
32 Mounting plate 7098852
33 Seal mounting plate (5 pc) 7098850
Spare parts 10
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 129
Pos. Description Product No.
58 Drawer 7099043
59 Drawer front 7099037
60 Controller connection plate 78186
61 On/off switch 7099041
62 Controller cover 73698
63
Boiler ident. module 24 kW 78223
Boiler ident. module 30 kW 78224
Boiler ident. module 45 kW 78225
Boiler ident. module 60 kW 78226
64 Cable harness low voltage 78193
65 Cable harness high voltage 7099957
66 O-ring (10 pc) 38434s
67 Sealing bush (set) 7099002
68 Cable harness of on/off switch 7099072
69 Cable harness BX holder 7099070
70 Fuse holder 38345
71 Seal Ø60 mm (5 pc) 7098878
72 O-ring set orifice 7099018
73 Seal (5 pc) 7099059
74 Set screw M5x20 (5 pc) 7099065
75 Cap 24/30 kW 79105
76 Double nipple THR x COMPR 75977
77 Cabel saddle (10 pc) 7098810
78 Bolt M6x16 (2 pc) 7099078
79 Clip pressure sensor 7101370
80 Drainplug 7099364
81 Cap connection piece 38498
82 Clip (5 pc) 73651s
83 Centering ring (5 pc) 73480s
84 Coupling nut pump 73481s
85 Seal pump (10 pc) 15022s
86 Coupling nut pump 15020
87 Conversion set pump 73149
88 Condensate drain set, incl. pos. 44 8718600686
Spare parts10
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications!130
Exploded view Logamax plus GB142-24/30
1
2
3
4
33
32
34
27 31
30
29
28
74
74
23
17
17
19
10
11
12
9
88
7
48
20
45
16
14
15
47
18
5
6
67
35
36 37
72 43
39
73
40
41
42
58
50
51
53
65
64
54
52
56
62
57
60
61
59
63
13
22
38
26
25
24
21
68
74
71
69
75
76
76
49
70
55
66
66
84
85
85
83
86
87
77
78
82
81
79
80
44
88
Spare parts 10
Logamax plus GB142-24/30/45/60 - We reserve the right to make any changes due to technical modifications! 131
Exploded view Logamax plus GB142-45/60
1
2
3
4
33
32
34
27 31
30
29
28
74
74
23
24
25
26
17
17
19
10
11
12
9
88
7
48
20
16
14
15
47
18
5
6
67
67
35
36
37
72 43
39
73
40
41
42
58
50
57
63
60
61
59
56
54
51
64
52
53
65
13
22
38
69
62
68
74
21
71
49
55
70
66
83
66
84
85
85
86
87
82
80
81
79
78
77
45
44
88
Unites States and Canada
Bosch Thermotechnology Corp.
50 Wentworth Avenue
Londonderry, NH 03053
Tel. 603-552-1100
Fax 603-584-1681
www.buderus.us
U.S.A.
Products manufactured by
Bosch Thermotechnik GmbH
Sophienstrasse 30-32
D-35576 Wetzlar
www.buderus.com
Bosch Thermotechnology Corp. reserves the right
to make changes without notice due to continuing
engineering and technological advances.
721.494A 0007

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